Obstretrics

Question 1

What are common symptoms for pregnant women (antenally)?

Answer 1

• Nausea
• Heartburn
• Constipation
• SOB
• Dizziness
• Swelling
• Backache
• Abdominal discomfort
• Headache

Question 2

What kind of advice/education can you give women antenatally?

Answer 2

• Provide information regarding the risks of smoking, alcohol and drug use during pregnancy
• Provide support through smoking cessation programmes
• Help with alcohol and drug problems may require specialist support (e.g. perinatal mental health teams)
• Parentcraft education (e.g. NCT) is a form of formal group discussion allowing couples to discuss issues relating to pregnancy, labour, delivery and care of the newborn

Question 3

What are the main risks of smoking in pregnant women?

Answer 3

• FGR
• Preterm labour
• Placental abruption
• Intrauterine foetal death

Question 4

What antenatal care is done in the first trimester?

Answer 4

• The first interaction with the health services is the booking visit
• A midwife will take a detailed history, examine the woman and perform a series of routine investigations
• If risk factors are identified, the woman may be referred to the hospital obstetric clinic or other specialist services

Question 5

Describe height and weight assessment of the woman in antenatal care?

Answer 5

• Height and weight should be recorded at the booking visit
• If the BMI is > 35, it is recommended that the women is reviewed by an obstetric consultant or another healthcare professional that can provide advice on increased pregnancy risks
• NOTE: there are differences in the recommended weight increase in pregnancy depending on the baseline BMI of the woman

Question 6

What are some general pregnancy advice regarding food? (RCOG Guidelines)

Answer 6

• Do NOT eat for two - maintain your normal portion size and try and avoid snacks
• Eat fibre-rich foods such as oats, beans, lentils, grains, seeds, fruit and vegetables as well as whole grain bread, brown rice and pasta
• Base your meals on starchy foods such as potatoes, bread, rice and pasta, choosing whole grain where possible
• Restrict intake of fried food, drinks and confectionary high in added sugars, and other foods high in fat and sugar
• Eat at least 5 portions of a variety of fruit and vegetables each day
• Dieting in pregnancy is NOT recommended but controlling weight gain in pregnancy is advocated

Question 7

What is some general exercise advice?

Answer 7

• Aerobic and strength conditioning exercises in pregnancy are considered beneficial and safe
• May help recovery following delivery, reduce back and pelvic pain during pregnancy and contribute to overall wellbeing
• Avoid contact sports
• Pelvic floor exercises during pregnancy may reduce the risk of urinary and faecal incontinence in the future
• It is safe to resume exercise after delivery once the woman feels comfortable

Question 8

Describe breastfeeding education

Answer 8

• WHO recommends:
  
  • Initiation of breastfeeding within an hour of birth
  • Exclusive breastfeeding for the first 6 months
  • Continued breastfeeding beyond 6 months at least up to 2 years of age
• Early education about breastfeeding is advocated to improve uptake and to engage women with breastfeeding services

Question 9

What are the options for pregnancy care?

Answer 9

• Home Birth
  
  • ADVANTAGES: familiar surroundings, no interruption of labour to go to hospital, no separation from family members, continuity of care
  • DISADVANTAGES: 45% of first-time mothers are transferred to hospital, poor perinatal outcome is twice as likely for home births, limited analgesic options
• Midwifery Units or Birth Centres
  
  • ADVANTAGES: continuity of care, fewer interventions, convenient location
  • DISADVANTAGES: 40% of nulliparous women require transfer to a hospital birth centre, limited access to analgesic options
• Hospital Birth Centre
  
  • ADVANTAGES: Midwives provide care during labour but doctors are available should the need arise
  • DISADVANTAGES: lack of continuity of care, greater likelihood of intervention

Question 10

Describe Antenatal Urine Tests

Answer 10

• An MSU should be sent for culture and sensitivity at the booking visit as a screening test
• Urinalysis is performed every antenatal visit
• Urine is screened for:
  
  • Protein - detect renal disease or pre-eclampsia
  • Persistent Glycosuria - pre-existing diabetes or gestational diabetes
  • Nitrites - detect UTIs
    
    • If nitrites are detected, an MSU is sent for MC&S to detect asymptomatic bacteriuria
    • Treatment will be initiated if a positive culture is found

Question 11

What is asymptomatic bacteriuria associated with?

Answer 11

• Increased risk of preterm delivery

- Increased risk of pyelonephritis during pregnancy

Question 12

How does blood pressure change in pregnancy and what does BP measurement in first trimester enable?

Answer 12

• Blood pressure falls a small amount in the first trimester
• It will rise to pre-pregnancy levels by the end of the second trimester
• Measurement of BP in the first trimester also allows identification of previously undiagnosed chronic hypertension
  
  • This allows early initiation of treatment (antihypertensives and aspirin)

Question 13

What are the booking tests in pregnancy?

Answer 13

• FBC: Haemoglobin, platelet count, mean cell volume
• MSU: Asymptomatic bacteriuria
• Blood group and antibody screen: Rhesus status and atypical antibodies
• Haemoglobinopathy screening: Screening is based on Family Origin Questionnaire and blood test results
• Infection screen: Hepatitis B, syphilis, HIV and rubella status
• Dating scan and first trimester screening: Accurate pregnancy dating with provision of risk assessment for trisomy 21, 18, 13 and identification of major congenital anomalies

Question 14

What is the purpose of FBC in booking bloods?
What is anaemia in pregnancy defined as?
What are additional investigations?

Answer 14

• Allows identification of anaemia
• NOTE: anaemia in pregnancy is defined as:
  
  • FIRST trimester < 110 g/L
  • SECOND and THIRD trimesters < 105 g/L
  • POSTPARTUM < 100 g/L
• If anaemia is detected, MCV should be examined to identify the likely cause
• Additional investigations include B12, folate or iron studies
• f iron deficiency anaemia, a trial of oral iron should be considered (an increase in Hb at 2 weeks suggests positive response)
• Women with a known haemoglobinopathy should have serum ferritin checked and offered oral supplements if ferritin < 30 mcg/L
• FBC may show low platelets (may be due to ITP)
• Gestational thrombocytopaenia rarely present in the first trimester
  
  • NOTE: it’s more common > 28 weeks
  • So, a low platelet count in the first trimester warrants further investigation
• A baseline platelet count is also useful later in pregnancy if the patient is suspected of having developed pre-eclampsia or HELLP syndrome

Question 15

Why is Blood Group requested in booking bloods?

Answer 15

• Mainly to identify Rhesus D-negative women
• These women should be informed about the risks of rhesus isoimmunisation and sensitisation from a RhD-positive baby
• Anti-D immunoglobulin is administered (ideally < 72 hours) in cases of potential sensitising events (e.g. CVS, amniocentesis, trauma)
• In pregnancies < 12 weeks, anti-D prophylaxis is only indicated if:
  
  • Ectopic pregnancy
  • Molar pregnancy
  • Therapeutic TOP
  • Uterine bleeding that is repeated, heavy or associated with abdominal pain
• Minimum dose of anti-D = 250 IU
• Women who are RhD-negative are offered prophylactic anti-D at 28 weeks
  
  • This can be done as a single large dose at 28 weeks
  • Or two doses at 28 and 34 weeks
• RhD-negative mothers will receive anti-D postpartum once the baby has been confirmed as being RhD-positive on cord blood testing

Question 16

How is gestational diabetes detected in booking bloods?

Answer 16

• Women with previous GDM should be offered a glucose tolerance test or random blood glucose in the first trimester
• This hopes to identify pre-existing diabetes that may have developed since the previous pregnancy

Question 17

Describe thalassaemia

Answer 17

• Autosomal recessive
• Alpha chains are produced by FOUR genes, two on each chromosome 16
• Severity of the disease depends on the number of alpha globin genes that are mutated
• Beta chains are produced by TWO genes, one on each chromosome 11
• Screening for thalassemia is offered to ALL pregnant women at the booking visit using the Family Origin Questionnaire (FOQ) and/or FBC results
• Those deemed at high risk will be referred to a foetal medicine unit to discuss options for more invasive testing

Question 18

Describe sickle cell screen

Answer 18

• Carrier rate of sickle cell trait (HbAS) is 1 in 10 in Afro-Caribbean people
• Carrier frequency of haemoglobin C trait is around 1 in 30
• HbSS is the most serious form with patients suffering chronic haemolytic anaemia and acute sickle cell crises
• People with HbSC have a milder features but are still at risk of sickle cell crises
• Partners should also be tested if at high risk

Question 19

Describe First Trimester Infection Screen

Answer 19

• Rubella
  
  • The screening programme for rubella immunity has been stopped because the levels of rubella in the UK are so low thanks to MMR
  • If a woman is identified as not being immune, they should be advised to avoid contact with individuals known to be currently infected
  • They should be offered the MMR vaccination following delivery
• Syphilis
  
  • In pregnancy, it can cause miscarriage or stillbirth
  • Women are routinely screened for syphilis
• Hepatitis B
  
  • Routinely screened in pregnancy to reduce infant infection
  • Without preventative measures, 90% of babies born to women with hepatitis B will contract the virus
  • If a baby is born to a woman with active hepatitis B, the infant should receive:
  • Hepatitis B vaccine
  • One dose of hepatitis B immunoglobulin within 12 hours
  • This confers 95% protection
  • Additional doses of hepatitis B vaccine will be needed at 1 and 6 months
• Hepatitis C
  
  • NOT routinely screened
  • May be offered to women at high risk (e.g. IVDU, HIV)
• HIV
  
  • Interventions to minimise transmission include:
    
    • Initiation of ART by 24 weeks if naïve
    • Planned elective C-section if viral load > 400 copies/mL at 36 weeks
    • Exclusive formula feeding from birth
  • Women who decline initial screening should be offered screening again at 28 weeks

Question 20

Describe Ultrasound for First Trimester Dating and Screening

Answer 20

• First trimester ultrasound is important for:
  
  • Dating
  • Identification of multiple pregnancies
  • Screening for trisomies
  • Examination of the foetus for gross anomalies (e.g. anencephaly, cystic hygroma)
• Best performed between 11+3 to 13+6 weeks
  
  • Crown-Rump Length (CRL) will be used to date the pregnancy during this phase
  • CRL will be expected to be 45-84 mm in this time
• From 14-20 weeks, the head circumference is used to date the pregnancy
• Beyond 20 weeks, genetic and environmental factors cause variability in foetal size so dating by ultrasound becomes progressively less accurate
• First trimester screening involves:
  
  • Measurement of nuchal translucency (NT)
    
    • Median if CRL 45 mm = 1.2 mm
    • Median if CRL 84 mm = 1.9 mm
  • Measurement of maternal b-hCG and PAPP-A (pregnancy-associated plasma protein A)
    
    • Trisomy 21: High b-hCG, low PAPP-A
    • Maternal age
• Using an algorithm taking into account the above three parameters, detects 90% of trisomy 21
• The false-positive rate can be reduced by additionally examining the nasal bone, ductus venosus flow and tricuspid flow
• Screening can also take place between 14-20 weeks using maternal biomarkers:
  
  • Alpha-fetoprotein
  • hCG
  • Unconjugated oestriol
  • Inhibin A
• NOTE: newer techniques like non-invasive prenatal testing are coming to the forefront

Question 21

What does NICE recommend for women at high risk of pre-eclampsia?

Which women are at high risk of pre-eclampsia?
What are moderate risk factors?

Answer 21

• 75 mg aspirin everyday from 12 weeks to delivery
• Women at HIGH risk:
  
  • High BP during previous pregnancy
  • Chronic kidney disease
  • Autoimmune diseases such as SLE and antiphospholipid syndrome
  • DM
  • Chronic hypertension
• Women with 2 or more moderate risk factors should also start aspirin
• Women at moderate risk:
  
  • Primiparity
  • Advanced maternal age (> 40 years)
  • Pregnancy interval of more than 10 years
  • BMI > 35 at booking visit
  • Family history of pre-eclampsia
  • Multifoetal pregnancy
• ALL women should be screened at every antenatal visit for pre-eclampsia by measurement of blood pressure and urinalysis for protein

Question 22

Which type of women are at risk of preterm birth

Answer 22

• Previous preterm birth
• Previous late miscarriage
• Multifoetal pregnancies
• Cervical surgery (e.g. cone biopsy)
• These women may be offered serial cervical length screening (with or without monitoring foetal fibronectin)

Question 23

From when does NICE recommend that SFH measurements should be made at every appointment?

Answer 23

• NICE recommend that SFH measurements should be performed at every antenatal appointment from 24 weeks
• If there are concerns of slow or arrested foetal growth, an ultrasound scan should be performed
• Typically, a dating scan is offered at the end of the first trimester and an anomaly scan at 20-22 weeks, but no further growth assessment unless clinically indicated

Question 24

Describe vitamin D screening

Answer 24

• NO routine screening
• Those at risk (e.g. obesity, skin colour) may be given vitamin D supplementation (oral cholecalciferol or ergocalciferol)
• NICE recommends that ALL pregnant and breastfeeding women should be advised to take 10 µg of vitamin D supplements daily

Question 25

Describe the Anomaly scan in Second Trimester Care

Answer 25

• Carried out at 20-22 weeks
• Mainly assessed foetal anatomy
• Conditions that may be identified:
  
  • Spina bifida
  • Major congenital anomalies
  • Diaphragmatic hernia
  • Renal agenesis

Question 26

What are the criteria for diagnosis and risk factors for gestational diabetes mellitus (Second Trimester Care)?

Answer 26

• Risk-based screening available in the UK
• Criteria for diagnosis of GDM:
  
  • Fasting plasma glucose > 5.6 mmol/L
  • 2-hour plasma glucose > 7.8 mmol/L
• Risk Factors
  
  • Previous GDM
  • Previous macrosomia
  • Raised BMI
  • First-degree relative with diabetes
  • Asian, black Caribbean or Middle-Eastern origin
• If risk factors are present, the woman should be offered a 2-hour 75 g oral glucose tolerance test (OGTT) at 24-28 weeks
• Women with a previous history of GDM should have an OGTT at 16-18 weeks and then a repeat should be performed at 24-28 weeks

Question 27

What is the Barker Hypothesis?

Answer 27

• There is an association between reduced foetal growth and increased susceptibility to several adult diseases (e.g. coronary heart disease, stroke and diabetes)

Question 28

What are the two ways of measuring foetal growth?

Answer 28

• Externally using a tape measure to assess uterine size from the superior edge of the pubic symphysis to the uterine fundus
• Using ultrasound to measure specific parts of the foetus and calculating estimated foetal weight (EFW)

Question 29

How is foetal size described?

Answer 29

• In terms of its size for gestational age and is presented on centile charts (NOTE: these vary depending on the population)

Question 30

What is SGA?

Answer 30

• Small for Gestational Age
• A foetus < 10th centile
• Many SGA foetuses may be constitutionally small (they have reached their growth potential)
• However, some SGA foetuses may have failed to reach their full growth potential - this is foetal growth restriction (FGR)
  
  • This is associated with significant increased risk of perinatal morbidity and mortality
  • Growth-restricted foetuses are at increased risk of intrauterine hypoxia/asphyxia
  • Therefore, they are more likely to be stillborn or have features of hypoxic ischaemia encephalopathy (HIE)
    
    • E.g. seizures, multi-organ failure
  • Other complications that they are at increased risk to in the neonatal period:
    
    • Hypoglycaemia
    • Hypothermia
    • Infection
    • Necrotising enterocolitis
  • Adult consequences: hypertension, cardiovascular disease and diabetes
• IMPORTANT: not all growth-restricted foetuses will be SGA - some may have a birthweight that is within the normal range for gestation but they may still have failed to reach their full growth potential

Question 31

What are determinants of foetal growth?

Answer 31

• Foetal growth is dependent on adequate delivery to, and transfer of nutrients and oxygen across, the placenta
• The placenta relies on appropriate maternal nutrition and placental perfusion
• Foetal hormones that affect metabolic rate, growth of tissues and maturation of individual organs are also important (e.g. insulin-like growth factors (IGF) is important in coordinating a precise and orderly increase in growth through late gestation)
• Insulin and thyroxine are required throughout late gestation

Question 32

What does foetal hyperinsulinaemia lead to for the foetus?

Answer 32

• Results in foetal macrosomia and excessive fat deposition
• This can lead to complications such as:
  • Stillbirth
  • Shoulder dystocia
  • Neonatal hypoglycaemia

Question 33

What are genetic influences (from the foetus itself) on foetal growth?

Answer 33

• Chromosomal defects
  
  • (e.g. Patau syndrome (trisomy 13) and Edward’s syndrome (trisomy 18))
• Sex
  
  • (Males have a higher birthweight)

Question 34

What are foetal epigenetic influences of foetal growth?

Answer 34

• These are modification of DNA which occur without any altering of the underlying sequence
• Genomic imprinting is an epigenetic process that silences one parental allele
• Evidence suggests that genes that are paternally expressed promote growth, whereas maternally expressed genes suppress growth

Question 35

How does infection in foetus affect foetal growth?

Answer 35

• Infections such as CMV, Toxoplasmosis and syphilis have been implicated in FGR
• If a foetus is found to be very small on USS, it is common to test maternal blood for antibodies to these infections and compare it with the results at booking to check whether the mother may have seroconverted during pregnancy (i.e. acute infection)

Question 36

What are maternal influences of foetal growth?

Answer 36

• Maternal height
• Pre-pregnancy weight
• Age
• Ethnicity
• Increasing parity (associated with increased birthweight)
• Teenage pregnancy (associated with FGR)
• Smoking, alcohol and recreational drug use (LBW)
• Cocaine (associated with spontaneous preterm birth, LBW and small head circumference)
  
  • Placental abruption is also associated with cigarette smoking and recreational drug use
• Chronic maternal disease (usually those that affect placental function or result in maternal hypoxia)
  
  • E.g. hypertension, cystic fibrosis, cyanotic heart disease
  • Maternal thrombophilia
  • Hypertension can lead to placental infarction

Question 37

What is placental insufficiency?
What are its causes?
What placental factors can affect foetal growth?

Answer 37

• Placental insufficiency occurs when there is inadequate transfer of nutrients and oxygen across the placenta to the foetus
• Causes include:
  
  • Poor maternal uterine artery blood flow
  • Thicker placental trophoblast barrier
  • Abnormal foetus villous development
• Placental infarction
• Acute premature separation (e.g. in placental abruption)
• Antepartum haemorrhage

Question 38

What four shunts ensure that oxygenated blood from the placenta is delivered to the foetal brain?

Answer 38

• Umbilical circulation
• Ductus venosus
• Foramen ovale
• Ductus arteriosus

Question 39

What does umbilical circulation do?

Answer 39

• Carries foetal blood to and from the placenta for gas and nutrient exchange
• Umbilical arteries arise from the caudal end of the dorsal foetal aorta
• They carry deoxygenated blood from the foetus to the placenta
• The umbilical vein returns oxygenated blood from the placenta to the foetal liver
• Usually there are:
  
  • 2 x foetal arteries
  • 1 x foetal vein
• A small proportion of blood is used to oxygenate the liver, but most of it will bypass the liver via the ductus venosus and joins the IVC
• Deoxygenated blood returning from the foetal head and lower body flows through the right side of the heart into the pulmonary artery
• It will then bypass the lungs and enter directly into the descending aorta via the ductus arteriosus
• This means that deoxygenated blood from the right ventricle will pass down the aorta and enter the umbilical arterial circulation to be returned to the placenta for oxygenation
• Before birth, the ductus arteriosus remains patent due to the production of prostaglandin E2 and prostacyclin (local vasodilators)
• Premature closure of the ductus arteriosus can be caused by COX inhibitors

Question 40

What happens to the umbilical circulation at birth?

Answer 40

• Cessation of umbilical blood flow causes cessation of flow into the ductus venosus
• This leads to a fall in pressure in the right atrium
• Which causes the closure of the foramen ovale
• Ventilation of the lungs opens the pulmonary circulation, causing a rapid fall in pulmonary vascular resistance
• This dramatically increases pulmonary circulation
• Ductus arteriosus closes within a few days of birth
• Sometimes, the transition from foetal to adult circulation is delayed, usually because the pulmonary vascular resistance fails to fall despite adequate breathing
• This is called persistent foetal circulation and results in LEFT-to-RIGHT shunting of blood from the aorta through the ductus arteriosus into the lungs
• The baby will be cyanosed and can suffer from life-threatening hypoxia
• This delay in closure of the ductus arteriosus is most commonly seen in preterm infants (< 37 weeks)
• It results in congestion of the pulmonary circulation and a reduction in blood flow to the GI tract and brain
  
  • It is also implicated in the pathogenesis of necrotising enterocolitis and intraventricular haemorrhage

Question 41

Describe central nervous system development in a foetus

Answer 41

• Neural development is one of the EARLIEST systems to start developing and one of the LAST to be completed
• It begins as a simple neural plate that folds to form a groove then a tube (initially open at each end)
• Failure of closure of these open ends leads to neural tube defects
• Later development of the foetal brain involves elaborate folding of the neurocortex (mainly in the 2nd half of pregnancy)
• There is a rapid increase in grey matter in the last trimester

Question 42

Describe resipratory system development in a foetus

Answer 42

• The lungs first appear as an outgrowth from the primitive foregut at about 3-4 weeks post-conception
• By 4-7 weeks, epithelial tube branches and vascular connections are forming
• By 20 weeks, the conductive airway tree and parallel vascular tree is well developed
• By 26 weeks, type I and type II epithelial cells are beginning to differentiate
• By 30 weeks, surfactant production has started
• Up to delivery, dilatation of the airspaces, alveolar formation and maturation of surfactant continues
• In utero the foetal lungs are full of fluid
• At birth
  
  • Production of this fluid ceases
  • Fluid is absorbed
  • Adrenaline appears to play a major role in this process
  • The clearance of fluid and the onset of breathing leads to a fall in pulmonary pressure and a rise in pulmonary blood flow
  • A consequent increase in left atrial pressure causes closure of the foramen ovale
• Surfactant prevents the collapse of small alveoli during expiration by lowering surface tension
• The main phospholipid in surfactant is phosphatidylcholine (lecithin) which accounts for 80% of total phospholipid
• Production of phosphatidylcholine is enhanced by:
  
  • Cortisol
  • Growth restriction
  • Prolonged rupture of membranes

Question 43

In what condition is surfactant production delayed?

Answer 43

• Maternal diabetes mellitus

Question 44

What does inadequate surfactant in developing fetus lead to?

Answer 44

• Poor lung expansion and poor gas exchange

Question 45

What happens to infants that are born preterm before producing enough surfactant?

Answer 45

• If infants are delivered preterm (before they produce enough surfactant) they will develop respiratory distress syndrome (RDS)
• This usually presents within the first few hours of life with signs of respiratory distress (e.g. tachypnoea and cyanosis)
• This occurs in 80% of infants born at 23-27 weeks

Question 46

What are the acute complications of RDS?

Answer 46

• Hypoxia/asphyxia
• Intraventricular haemorrhage
• Necrotising enterocolitis

Question 47

How can incidence and severity of RDS be reduced?

Answer 47

• Administering steroids antenatally to mother at risk of preterm delivery
• The steroids will cross the placenta and stimulate premature release of stored foetal pulmonary surfactant in the foetal alveoli

Question 48

Describe foetal breathing movements

Answer 48

• Several intermittent foetal breathing movements (FBM) occur in utero especially during REM sleep
• These movements help maintain a high level of lung expansion that is essential for normal lung growth and maturation
• During the apnoeic episodes in between FBM, active laryngeal constriction opposes lung recoil by preventing the escape of lung liquid via the trachea
• Prolonged absence or impairment of FBM is likely to result in reduced mean lung expansion and can lead to hypoplasia of the lungs

Question 49

What are causes of pulmonary hypoplasia?

Answer 49

• Oligohydramnios
• Decreased intrathoracic space (e.g. diaphragmatic hernia)
• Chest wall deformities

Question 50

Describe alimentary system development in a foetus

Answer 50

• The primitive gut consists of the foregut, midgut and hindgut
• It is suspended by a mesentery through which the blood supply, lymphatic and nerves reach the gut parenchyma
• The foregut endoderm gives rise to:
  
  • Oesophagus
  • Stomach
  • Proximal half of duodenum
  • Liver
  • Pancreas
• The midgut endoderm gives rise to:
  
  • Distal half of duodenum
  • Jejunum
  • Ileum
  • Caecum
  • Appendix
  • Ascending colon
  • Transverse colon
• The hindgut endoderm gives rise to:
  
  • Descending colon
  • Sigmoid colon
  • Rectum
• Between weeks 5-6, due to a rapidly enlarging liver and elongation of the intestines accompanied by a lack of space in the small abdomen, the midgut extrudes into the umbilical cord as a physiological hernia
• Whilst herniated, the gut will undergo rotation and then re-enter the abdominal cavity by 12 weeks gestation

Question 51

What does failure of the gut to re-enter the abdominal cavity results in?

Answer 51

• Omphalocele (exomphalos)

Question 52

What are other malformations in alimentary system development?

Answer 52

• Failure of normal rotation (malrotation)
  
  • Malrotation can result in volvulus and bowel obstruction
• Fistulae
  
  • MOST COMMON: tracheo-oesophageal fistula
  • Some children with tracheo-oesophageal fistula also have other congenital abnormalities (e.g. VACTERL)
• Atresias
  
  • When a segment of bowel has a lumen that is NOT patent
  • Usually occur in the upper GI tract (e.g. oesophagus or duodenum)
  • The foetus continuously swallows amniotic fluid, so an obstruction that prevent passage of the amniotic fluid through the GI tract will cause polyhydramnios

Question 53

After the physiological hernia, what happens next in alimentary system development?

Answer 53

• Peristalsis in the intestines occurs from the 2nd trimester
• The large bowel will be filled with meconium at term
• Defecation in utero, and hence meconium in the amniotic fluid, is associated with:
  
  • Post-term pregnancies
  • Foetal hypoxia
• Aspiration of meconium-stained liquor by the foetus at birth can cause meconium aspiration syndrome or RDS
• In the last trimester, water content decreases and glycogen and fat stores increase about fivefold
  
  • As such, preterm infants have virtually no fat and have a reduced ability to withstand starvation
  • This can be compounded by poor sucking, uncoordinated swallowing mechanisms, delayed gastric emptying and poor absorption
  • Growth-restricted foetuses also have reduced glycogen stores
  • These infants are more prone to hypoglycaemia

Question 54

Describe the liver, pancreas and gallbladder in alimentary system development

Answer 54

• They derive from the foregut endoderm
• The liver and biliary tree appear late in the 3rd week as the hepatic diverticulum (an outgrowth from the ventral wall of the distal foregut)
• The larger portion of this diverticulum gives rise to the parenchymal cells (hepatocytes) and the hepatic ducts
• The smaller portion becomes the gallbladder
• By the 6th week, the foetal liver performs haematopoiesis
  
  • This will peak at 12-16 weeks and continue until 36 weeks
• In utero the normal metabolic functions of the liver are performed by the placenta (e.g. unconjugated bilirubin from haemolysis in the foetus is transferred to the mother rather than being conjugated in the foetus)
• The foetal liver is less able to conjugated bilirubin than the adult liver because of deficiencies of enzymes (e.g. UGT)
  
  • After birth, the loss of the placenta and this immature ability to conjugate bilirubin (particularly in premature infants) may results in transient unconjugated hyperbilirubinaemia (physiological jaundice)
• Glycogen is stored in small quantities in the liver from the 1st trimester and peaks in the 3rd trimester
• Growth-restricted and premature infants have deficient glycogen stores (therefore, they are prone to hypoglycaemia)

Question 55

Describe kidney and urinary tract development

Answer 55

• The permanent final form of the kidney (metanephric kidney) is preceded by the development and regression of two primitive forms: pronephros and mesonephros
• Pronephros originates at about 3 weeks in a ridge that forms on either side of the midline in the embryo (nephrogenic ridge)
• In this region, epithelial cells will arrange themselves in a series of tubules and join laterally with the pronephric duct
• The pronephros is non-functional
• Each pronephric duct will grow towards the tail of the embryo during which it will induce intermediate mesoderm in the thoracolumbar area to become mesonephric tubules
• The prenephros will then degrade whilst the mesonephric (Wolffian) duct extends towards the most caudal end of the embryo, ultimately attaching to the cloaca
• During the 5th week, the ureteric bud develops as an outpouching from the Wolffian duct
• This bud grows into the intermediate mesoderm and branches to form the collecting duct system (ureter, pelvis, calyces and collecting ducts) of the kidney
• It also induces the formation of the renal secretory system (glomeruli, convoluted tubules, loops of Henle)
• Then, the lower portions of the nephric duct will migrate caudally and connect with the bladder, thereby forming the ureters
• As the foetus develops, the torso elongates and the kidneys rotate and migrate upwards within the abdomen causing the length of the ureters to increase

Question 56

What can failure of normal kidney migration lead to?

Answer 56

• A pelvic kidney

Question 57

What can abnormal development of the collecting duct system in kidneys lead to?

Answer 57

• Duplications such as duplex kidneys

Question 58

What is a posterior urethral valve?

Answer 58

• An obstructing membrane in the posterior male urethra
• SEVERE obstruction in utero can lead to hydronephrosis and renal interstitial fibrosis
• Although the structures of the urinary system are in place by 32-36 weeks, the excretory and concentrating ability of the foetal kidneys is gradual and continues after birth
• In preterm infants, this may result in abnormal water, glucose, sodium and acid-base homeostasis

Question 59

What does renal agenesis lead to?

What does bilateral renal agenesis cause and what is this condition associated with?

Answer 59

• oligohydramnios (because foetal urine forms much of the amniotic fluid)
• Bilateral renal agenesis causes Potter’s syndrome which is associated with:
  • Widely-spaced eyes
  • Small jaw
  • Low set ears
  • Secondary oligohydramnios
  • Renal failure (and death)
  • Pulmonary hypoplasia (secondary to oligohydramnios)

Question 60

How does the skin develop in a foetus?

Answer 60

• The skin and its appendages develop from ectodermal and mesodermal germ layers
  
  • Epidermis = comes from the surface ectoderm
  • Dermis and Hypodermis = mesenchymal cells in the mesoderm
• By 4 weeks gestation, a single-cell layer of ectoderm surrounds the embryo
• At 6 weeks, the ectodermal layer differentiates into an outer periderm and an inner basal layer
  
  • The periderm will slough off as vernix
  • The basal layer produces the epidermis and the glands/nails/hair follicles
• Eventually the epidermis becomes stratified and by 16-20 weeks, all layers of the epidermis are developed
• Preterm babies have NO vernix and thin skin
  
  • This leads to increased insensible fluid loss
  • They also have poor thermal control due to having a large surface area to body weight ratio and little insulation
  • They also have immature vascular tone meaning that they can’t use peripheral vasoconstriction to limit heat loss
• Hair follicles develop as hair buds at around 12-16 weeks
• By 24 weeks, the hair follicles are producing lanugo hair
  
  • This is usually shed before birth

Question 61

Describe blood and immune system development

Answer 61

• RBCs and immune cells are derived from pluripotent haematopoietic cells which are first found
  
  • Initially, in the blood islands of the yolk sac
  • By 8 weeks, the yolk sac is replaced by the liver as the source of blood cells
  • By 20 weeks, all cells are produced by the bone marrow
• T cell precursors transit to the thymus by 9 weeks gestation
• The mature naïve and memory T cells will be found in the spleen and lymph nodes at 12-14 weeks
• Circulating mature T cells are present from 16 weeks
• In the second trimester there are more Tregs than at any other point in life because it is important in the induction of tolerance
• B cells appear in the circulation by around 12 weeks
• They will then undergo functional maturation in secondary lymphoid tissue
• Much of the IgG in the foetus will be from the mother
• The foetus produces small amounts of IgA and IgM
• Detection of IgM or IgA in the newborn without IgG is suggestive of foetal infection

Question 62

Describe haemoglobin development

Answer 62

• Most haemoglobin is HbF (2 alpha + 2 gamma)
• Adult haemoglobins are either:
  
  • HbA (2 alpha + 2 beta)
  • HbA2 (2 alpha + 2 delta)
• Up to 28 weeks gestation, 90% of foetal Hb is HbF
• From 28-34 weeks there is a switch to HbA
• At term, the ratio of HbF to HbA is 80:20
• By 6 months, only 1% is HbF
• HbF has a higher affinity for oxygen
• Infants also have a higher haemoglobin concentration which enhances transfer of oxygen across the placenta
• Abnormal haemoglobin production results in thalassemia
  
  • This is a group of disorder characterised by reduced or absent production of the globin chains (e.g. beta-thalassemia is caused by reduced or absent production of beta-globin)

Question 63

Describe endocrine system development

Answer 63

• Major components of the hypothalamo-pituitary axis are in place by 12 weeks
• Testosterone is produced in the first trimester, increasing to 17-21 weeks which mirrors the development of the male urogenital tract
• Growth restricted foetuses exist in a state of relative hypothyroidism (may be a compensatory measure to decrease metabolic rate and oxygen consumption)

Question 64

Describe foetal behavioural states

Answer 64

• First activity is beating of the foetal heart
• Foetal movements = 7-8 weeks
  
  • These will begin as discernible movements, and progress to startles, movements of arms and legs and breathing movements
• By 12 weeks, yawning, sucking and swallowing can be seen
• From this point onwards, no new behaviours are acquired but their patterns change
• There are FOUR foetal behavioural states
  
  • 1F - quiescence (like non-REM sleep in a neonate)
  • 2F - frequent and periodic gross body movements with eye movements (like REM sleep)
  • 3F - no gross body movements but eye movements (like quiet wakefulness)
  • 4F - vigorous continual activity with eye movements (like active wakefulness)

Question 65

Describe amniotic fluid in foetal development

Answer 65

• By 12 weeks, the amnion comes into contact with the inner surface of the chorion and the two surfaces become adherent (but they never fuse)
• The amnion and chorion do NOT contain vessels or nerves but they contain a significant quantity of phospholipids as well as enzymes involved in phospholipid hydrolysis
• Choriodecidual function is thought to be important in the initiation of labour by the production of prostaglandins E2 and F2a
• Amniotic fluid is initially secreted by the amnion
• By the 10th week, it is mainly transudate of foetal serum via the skin and umbilical cord
• From 16 weeks, the foetal skin becomes impermeable to water
• The net increase in amniotic fluid thereafter is due to contributions through the kidneys and lung fluids
• Removal of amniotic fluid is by foetal swallowing
• Amniotic fluid contains growth factors and multipotent stem cells (although the function is uncertain)

Question 66

What are the changes in amniotic fluid volume?

Answer 66

• Increase in amniotic fluid volume
  
  • 10 weeks = 30 ml
  • 20 weeks = 300 ml
  • 30 weeks = 600 ml
  • 38 weeks = 1000 ml
• IMPORTANT: from term, there is a rapid fall in amniotic fluid volume
  
  • 40 weeks = 800 ml
  • 42 weeks = 350 ml

Question 67

What are the functions of amniotic fluid?

Answer 67

• Protect the foetus from mechanical injury
• Permit movement of the foetus while preventing limb contracture
• Prevent adhesions between foetus and amnion
• Permit foetal lung development in which there is two-way movement of fluid into the foetal bronchioles (absence of amniotic fluid in the second trimester is associated with pulmonary hypoplasia)

Question 68

What are causes of oligohydramnios?

Answer 68

• Renal agenesis
• Cystic kidneys (PCKD)
• FGR

Question 69

What are the causes of polyhydramnios?

Answer 69

• Congenital neuromuscular disorders
• Anencephaly
• Oesophageal/duodenal atresia (prevents swallowing of amniotic fluid)

Question 70

What is transvaginal ultrasonography useful for?

Answer 70

• It isuseful in early pregnancy, for examining the cervix later in pregnancy and for identifying the lower edge of the placenta
• It is also useful in women who have a lot of adipose tissue
• In general, after around 12 weeks, an abdominal transducer will be used

Question 71

What is acoustic impedance?

Answer 71

• Related to the density of tissues

Question 72

How does doppler ultrasound work?

Answer 72

• It allows assessment of the velocity of blood within the foetal and placental vessels (thus providing an indirect assessment of foetal and placental condition)

Question 73

When can the gestational sac, yolk sac, embryo and beating of the heart be observed? (Early Pregnancy)

Answer 73

• The gestational sac can be visualised from 4-5 weeks
• The yolk sac can be visualised at about 5 weeks
• The embryo can be observed and measured at 5-6 weeks
• Beating of the heart can be seen at 6 weeks

Question 74

How is transvaginal ultrasound important in early pregnancy?

Answer 74

• It is important in early pregnancy to diagnose disorders of early pregnancy (e.g. incomplete or missed miscarriage, blighted ovum where no foetus is present and ectopic foetus)

Question 75

What is a Blighted Ovum?

Answer 75

• The gestational sac is present but it is empty because the foetus has not developed

Question 76

What is the determination of Gestational Age and Assessment of Foetal Size and Growth?

Answer 76

• Crown-Rump Length (CRL) is used up to 13 weeks + 6 days
• Head Circumference is used from 14-20 weeks
• Biparietal diameter and femur length can also be used to assess gestational age
• The earlier the measurement is made, the more accurate the prediction
• Later on in pregnancy, measuring foetal abdominal circumference and head circumference will help assess size and growth
• In addition to AC and HC, BPD and FL can be combined in an equation to give a more accurate estimate of foetal weight than any of the parameters on their own
• In foetuses at risk of growth restriction, serial measurements are plotted
• This also helps differentiate between types of growth restriction (e.g. symmetrical vs asymmetrical)
• Cessation of growth is suggestive of placental failure
• Gestational age can no longer be accurately calculated by ultrasound after 20 weeks (because of a broad range in normal values)

Question 77

What is chorionicity?

What are monochorionic twin pregnancies at higher risk of

Answer 77

• It is important in determining the chorionicity (number of placentas) of the pregnancy
• Monochorionic twin pregnancies (i.e. sharing a placenta) are at increased risk of pregnancy complications (e.g. twin-to-twin transfusion syndrome and higher rates of perinatal mortality)
• Dichorionic twins have a thicker dividing membrane (formed of two layers of amnion and two layers of chorion) - this can be viewed on ultrasound
• The best time to perform the ultrasound to determine chorionicity is 9-10 weeks
• Ultrasound is also useful for confirming growth restriction, foetal anomaly and the presence of placenta praevia (more common in twins)

Question 78

When can foetal structural abnormalities be diagnosed?

What are common examples of foetal abnormalities?

Answer 78

• Major foetal structural abnormalities can be diagnosed by US at or before 20 weeks
• Common examples
  
  • Spina bifida
  • Hydrocephalus
  • Skeletal abnormalities (e.g. achondroplasia)
  • Abdominal wall defects (e.g. gastroschisis)
  • Cleft lip/palate
  • Congenital cardiac abnormalities
• These are usually detected at the 20-week anomaly scan
• Factors affecting sensitivity of the scan include the woman’s BMI and position of the baby at the time of the scan
• Repeat scans may be required if visualising certain structures is difficult

Question 79

What is placenta praevia?

Answer 79

• When a placenta is inserted into the lower segment of the uterus and can cause life-threatening haemorrhage in pregnancy
• US scans are very useful in the localisation of the site of the placenta
• US scans can identify the lower edge of the placenta (transvaginal is better than transabdominal)
• About 15-20% of women will have a low-lying placenta at 20 weeks, but only 10% of this group will eventually develop placenta praevia

Question 80

Describe Amniotic Fluid Assessment

Answer 80

• US scans can be used to assess increased and decreased amniotic fluid volumes
• The foetus swallows amniotic fluid, absorbs it in the GI tract and excretes urine into the amniotic sac
• Congenital abnormalities that impair the ability of the foetus to swallow (e.g. oesophageal atresia, anencephaly) results in INCREASED amniotic fluid volume
• Congenital abnormalities that cause a failure of urine production (e.g. renal agenesis, posterior urethral valves) will result in REDUCED amniotic fluid

Question 81

What are the TWO ultrasound measurement approaches that give an indication of amniotic fluid volume?

Answer 81

• Maximum vertical pool
• Amniotic fluid index
• Amniotic fluid volume is reduced in FGR, because of redistribution of foetal blood away from the kidneys to vital structures like the brain and heart (this leads to reduced renal perfusion and GFR)

Question 82

Describe Assessment of Foetal Wellbeing

Answer 82

• Evaluating foetal movements, tone and breathing can give an indication of foetal wellbeing
• Doppler ultrasound can give an indication of placental function

Question 83

How is cervical length measured?

Answer 83

• Cervical length can be measured best using a transvaginal probe
• 50% of women who deliver before 34 weeks have a short cervix at midtrimester
• NICE recommends serial measurements of cervical length from 16 weeks in women with a history of spontaneous preterm birth or midtrimester loss

Question 84

What other obstretric conditions are US scans useful for?

Answer 84

• Confirmation of intrauterine death
• Confirmation of foetal presentation in uncertain cases
• Diagnosis of uterine and pelvic abnormalities during pregnancy (e.g. fibromyomata and ovarian cysts)

Question 85

What is the Ultrasound schedule according to NICE?

Answer 85

NICE recommends that all pregnant women should be offered scans at:

• 10-14 weeks
  
  • Mainly to determine gestational age, detect multiple pregnancy and determine nuchal translucency as part of screening for Down syndrome
• 18-21 weeks
  
  • Primarily screens for structural anomalies
  • Give couples reproductive choice (e.g. termination of pregnancy)

Question 86

Describe Cardiotocography

Answer 86

• A CTG is a continuous trace of the foetal heart rate that is used to assess foetal wellbeing
• It is sometimes called electronic foetal monitoring (EFM)
• It is performed whilst the pregnant woman is in the left lateral or semi-recumbent position
• Two external transducers are placed on the mother’s abdomen, each attached with a belt
• One transducer is a pressure-sensitive contraction tocodynometer (stretch gauge) which measures the pressure required to flatten a section of the abdominal wall
  
  • This correlates with the internal uterine pressure and indicates if there is any uterine activity (contractions)
• The second transducer uses ultrasound and the Doppler effect to detect motion of the foetal heart
  
  • It allows continuous assessment of the foetal heart rate
• Recordings are taken for 30 mins
• The output from the CTG machine produces TWO lines
  
  • A tracing of the foetal heart rate
  • A tracing of uterine activity

Question 87

What are important CTG features?

Answer 87

• Pathological events like hypoxia modify the signals to the foetal heart resulting in changes in the heart rate patterns
• Features reported on a CTG
  • Baseline rate
  • Baseline variability
  • Accelerations
  • Decelerations

Question 88

What is a normal foetal heart rate?

What are causes of foetal tachycardia?

Answer 88

• Normal foetal heart rate = 110-150 bpm
• Foetal heart rate decreases with advancing gestational age
• 160 bpm is considered the upper limit of normal
• Baseline rate is determined over 5-10 mins
• Causes of foetal tachycardia
  
  • Maternal or foetal infection
  • Acute foetal hypoxia
  • Foetal anaemia
  • Drug (e.g. ritodrine)

Question 89

Describe Baseline Variability

Answer 89

• In normal physiological conditions, the interval between successive foetal heart beats varies
• This is called short-term variability and is increases with gestational age
• It is not visible on a standard CTG but can be measured by computer
• There are also longer-term fluctuations in heart rate occurring 2-6 times per minute, known as baseline variability
• Normal baseline variability is suggestive of a normal foetal autonomic system
• Baseline variability is considered abnormal if it is < 10 bpm
• Foetuses have 20-30 min deep sleep cycles so baseline variability may be normally reduced for this length of time (but should be preceded and followed by a normal CTG)

Question 90

What factors affect baseline variability?

Answer 90

• Foetal sleep states and activity
• Hypoxia
• Foetal infection
• Drugs (e.g. opioids)

Question 91

What are foetal heart rate accelerations?

Answer 91

• These are increases in baseline foetal heart rate of at least 15 bpm lasting for at least 15 seconds
• The presence of 2 or more accelerations on a 20-30 min antepartum foetal CTG defines a reactive trace and is indicative of a non-hypoxic foetus

Question 92

What are foetal heart rate decelerations?

Answer 92

• These are transient reductions in foetal heart rate of at least 15 bpm, lasting more than 15 seconds
• Causes
  • Foetal hypoxia
  • Umbilical cord compression

Question 93

What is a normal CTG?

Answer 93

• Baseline heart rate of 110-150 bpm
• Baseline variability exceeding 10 bpm
• More than 1 acceleration in a 20-30 min tracing

Question 94

What is a biophysical profile?

Answer 94

• A biophysical profile (BPP) takes into account FIVE acute foetal variables (of which 4 are shown on ultrasound):
  
  • Foetal breathing movements (FBMs)
  • Foetal gross body movement
  • Foetal tone
  • CTG
  • Amniotic fluid volume
• A score of 2 (normal) or 0 (sub-optimal) is assigned to each of the variables giving the foetus a score between 0 and 10
• A score of 8-10 is NORMAL
• A score of 6 is borderline and requires a repeat to exclude a period of foetal sleep as a cause
• There is insufficient evidence to support the use of BPP as a test of foetal wellbeing in high-risk pregnancies

Question 95

Describe Umbilical Artery Doppler Investigations

Answer 95

• Waveforms from the umbilical artery provide information on placental resistance to blood flow, and hence an indicator of placental health
• E.g. an infarcted placenta secondary to maternal hypertension will have increased blood flow
• In cases of a diseased placenta, the placenta wont allow blood to flow freely through it, and therefore there will be a backlog of blood in the umbilical artery
• In a diseased placenta, blood flow in the umbilical artery during diastole may be reduced, absent or reversed
• Reversed end-diastolic flow means that, during diastole, blood is flowing away from the placenta back to the foetus
  
  • It is associated with foetal hypoxia and intrauterine death
• In other words, low diastolic flow indicates high resistance
• Indices such as pulsatility index or resistance index are useful as they calculate the variability of blood velocity in a vessel (high indices suggests high resistance to blood flow)
• Normally, diastolic blood flow through the umbilical artery increases through gestation

Question 96

Describe Foetal Vessel Doppler Investigations

Answer 96

• Falling oxygen levels in the foetus leads to redistribution of blood flow to the essential organs (e.g. brain, heart, adrenals)
• This is often called cerebral redistribution
• As hypoxia worsens, the pulsatility index in the middle cerebral artery will fall, indicating increasing diastolic flow
• There will also be increased resistance in the foetal aorta (thus reducing blood flow to the rest of the body)
• Absent diastolic flow in the foetal aorta is suggestive of foetal acidaemia
• The most sensitive index of foetal acidaemia and impending heart failure is increasing pulsatility in the central veins supplying the heart (e.g. ductus venosus, inferior vena cava)
• The ductus venosus flow reflect atrial pressure-volume changes
• As FGR worsens, hypoxia and acidaemia affects cardiac function, leading to increased preload and afterload
• This leads to reduce velocity in the ductus venosus A-wave which is suggestive of increasing end-diastolic pressure
• A retrograde ductus venosus A-wave is suggestive of overt cardiac compromise and may require early delivery
• The velocity of blood flow in the middle cerebral artery is an indicator of foetal anaemia
  
  • When the foetus is anaemic, the peak systolic velocity increases
  • This is useful in Rhesus isoimmunistion disease and twin-to-twin transfusion syndrome

Question 97

What can uterine artery dopplers be used for?

Answer 97

• Predict at-risk pregnancies e.g. pre-eclampsia
• Doppler ultrasound of the uterine arteries may show markers of increased resistance
• High resistance patterns are associated with:
  
  • Pre-eclampsia
  • GFR
  • Placental abruption
• These pregnancies will need close monitoring of foetal growth rate and the possible development of maternal hypertension

Question 98

What is the Cerebroplacental ratio?

Answer 98

• This is the ratio of the pulsatility indices of the middle cerebral artery and the umbilical artery
• Foetuses with an abnormal ratio that are appropriately grown for gestational age or have late-onset SGA (> 34 weeks) have a higher incidence of abnormal intrapartum CTG requiring emergency Caesarean section, lower cord pH and an increased rate of admission to NICU
• In foetuses with early-onset SGA, an abnormal ratio is associated with an increased rate of adverse neonatal outcome and perinatal death

Question 99

What is US necessary for? (Procedures)

Answer 99

• Amniocentesis, chorion villus sampling and cordocentesis

- It is also necessary for therapeutic procedures such as inserting foetal bladder shunts or chest drains

Question 100

What is pre-eclampsia often associated with in the foetus?

Answer 100

• Foetal growth restriction
• Women entering pregnancy with chronic hypertension have an increased risk to both the mother and the baby (e.g. pre-eclampsia and FGR)

Question 101

How do you classify the severity of hypertension?

Answer 101

• MILD = 140-149 systolic, 90-99 diastolic
• MODERATE = 150-159 systolic, 100-109 diastolic
• SEVERE = > 160 systolic, > 110 diastolic

Question 102

What are the three conditions which pregnant women presenting with hypertension in pregnancy have?

Answer 102

• Non-proteinuric pregnancy-induced hypertension
• Pre-eclampsia
• Chronic hypertension

Question 103

Describe non-proteinuric pregnancy-induced hypertension

Answer 103

• Hypertension that arises for the first time in the second half of pregnancy in the absence of proteinuria
• It is NOT associated with adverse pregnancy outcomes
• Mild-to-moderate increases in blood pressure in this setting do NOT require treatment
• IMPORTANT: 1/3 of women with gestational hypertension will develop pre-eclampsia

Question 104

What is chronic hypertension?
What are the different types of chronic hypertension?
What can chronic hypertension predispose to?
Why may chronic hypertension be masked in pregnancy?

Answer 104

• Women who have confirmed hypertension in the first half of pregnancy are likely to have chronic hypertension
• Most will have essential hypertension, but secondary causes should be excluded
• Chronic hypertension can predispose to the development of pre-eclampsia
• Even without pre-eclampsia, chronic hypertension is associated with increased maternal and foetal morbidity
• IMPORTANT: the physiological fall in blood pressure that occurs in the first trimester due to peripheral vasodilation can mask chronic hypertension

Question 105

What is pre-eclampsia?

Answer 105

• Hypertension of at least 140/90 mm Hg recorded on at least 2 separate occasions and at least 4 hours apart and in the presence of at least 300 mg protein in a 24-hr collection of urine, arising de novo after the 20th week of pregnancy in a previously normotensive woman and resolving completely by the 6th postpartum week
• 2-3% of all pregnancies

Question 106

What are the risk factors of pre-eclampsia?

Answer 106

• First pregnancy
• Multiparous with a previous history of pre-eclampsia
• 10 years or more since last baby
• Age 40 years or more
• BMI > 35
• Family history of pre-eclampsia in mother or sister
• Booking diastolic pressure of 80 mmHg or more
• Booking proteinuria (of >= 1 + on more than one occasion or quantified at >= 0.3g/24 h
• Multiple pregnancies
• Certain underlying medical conditions
• Antiphospholipid syndrome
• Coarctation of the aorta
• NOTE: the protective effect of first pregnancy is lost if a woman has a child with a new partner

Question 107

Why is trophoblast tissue associated with pre-eclampsia?

Answer 107

• Pre-eclampsia can occur in pregnancies lacking a foetus (molar pregnancies) and in the absence of a uterus (abdominal pregnancies)
• This suggests that the trophoblast tissue provides the stimulus for the disorder

Question 108

What is the two stage process of pre-eclampsia?

Answer 108

Stage 1
- Trophoblast invasion is patchy

• Spiral arteries retain their muscular walls
• This prevents the development of a high-flow, low-impedance uteroplacental circulation
• This leads to uteroplacental ischaemia

Stage 2
- Uteroplacental ischaemia results in oxidative and inflammatory stress

• Involvement of secondary mediators leads to endothelial dysfunction, vasospasm and activation of the coagulation system
• Because the target cell of the disease process (vascular endothelial cell) is so ubiquitous, pre-eclampsia is a multisystem disorder

Question 109

Describe pre-eclamspia and the cardiovascular system

Answer 109

• In normal pregnancy, peripheral vasodilation —> decreased total peripheral resistance despite an increase in plasma volume and HR
• In pre-eclampsia: peripheral vasoconstriction –> hypertension
• Increased BP and loss of endothelial cell integrity leads to increased vascular permeability —> oedema

Question 110

How does pre-eclampsia affect the renal system?

Answer 110

• A lesion called glomeruloendotheliosis is seen (specific for pre-eclampsia)
• Associated with impaired glomerular filtration and selective protein loss (albumin and transferrin) leading to proteinuria
• This leads to a reduction in plasma oncotic pressure which exacerbated the oedema

Question 111

How does pre-eclampsia affect the haematological system?

Answer 111

• Diffuse vascular damage in pre-eclampsia is associated with laying down of fibrin and the adherence of platelets
• Pre-eclampsia is associated with increased fibrin deposition and a reduced platelet count

Question 112

How does pre-eclampsia affect the liver?

Answer 112

• Subendothelial fibrin deposition is associated with elevation of liver enzymes
• This can be associated with haemolysis and low platelet count
• This is called HELLP Syndrome
  
  • Haemolysis
  • Elevated Liver enzymes
  • Low Platelets
• HELLP syndrome is a particularly severe form of pre-eclampsia
• It is associated with a high foetal loss rate

Question 113

What do women with HELLP syndrome present with?

Answer 113

• Epigastric pain

- Nausea and vomiting

Question 114

What are the severe complications of HELLP syndrome

Answer 114

• Acute renal failure
• Placental abruption
• Stillbirth

Question 115

How does pre-eclampsia affect the neurological system?

Answer 115

• Presence of tonic-clonic convulsions
  
  • No other identifiable cause
• Likely to be due to vasospasm and cerebral oedema

Question 116

What is the clinical presentation of pre-eclampsia?

Answer 116

• Classic symptoms
  
  • Frontal headache
  • Visual disturbance
  • Epigastric pain
  • Vague ‘flu-like’ symptoms
• Hypertension is usually the first sign
• Rapidly progressive oedema of the face and hands may suggest pre-eclampsia
  
  • NOTE: dependent oedema of the feet is very common in pregnancy
• Epigastric tenderness suggest liver involvement (worrying)
• Neurological examination may show hyperreflexia and clonus in severe cases
• Urine protein should be tested as part of the examination

Question 117

What is the management of pre-eclampsia?

Answer 117

• There is NO CURE for pre-eclampsia other than to end the pregnancy by delivering the baby
• This can be a major problem if pre-eclampsia occurs early in pregnancy (particularly < 34 weeks)

Question 118

What are the principles of pre-eclampsia management?

Answer 118

• Early recognition of the symptomless syndrome
• Awareness of the serious nature of the condition in its severest form
• Adherence to agreed guidelines for admission to hospital, investigation and the use of antihypertensive and anticonvulsant therapy
• Well-timed delivery to pre-empty serious maternal or foetal complications
• Post-natal follow-up and counselling for future pregnancies

Question 119

What are the investigations for pre-eclampsia? (both in mother and foetus)

Answer 119

• To monitor for MATERNAL complications
  
  • FBC (focus on falling platelet count and rising Hct)
  • Clotting studies (of platelet count is abnormal)
  • Serum renal profile
  • Serum liver profile
  • Frequent repeat proteinuria quantification
• To monitor for FOETAL complications
  
  • Ultrasound assessment of:
    
    • Foetal size
    • Amniotic fluid volume
    • Maternal and foetal Doppler scan
  • Antenatal CTG

Question 120

What is the treatment of hypertension?

Answer 120

• The most common cause of death in women who die of pre-eclampsia is cerebral bleeding secondary to uncontrolled SBP
• Antihypertensive therapy aims to lower blood pressure to reduce the risk of a maternal CVA without compromising uterine blood flow
• Labetalol (alpha-blocker) is the drug of choice in most guidelines
• Nifedipine (CCB) has a rapid onset of action but can cause a severe headache which mimics worsening disease
• In SEVERE cases, IV hydralazine or labetalol can be used

Question 121

What is the treatment and prevention of eclampsia?

Answer 121

• IV magnesium sulphate is the drug of choice
• Used prophylactically in women with severe pre-eclampsia
• Loading IV dose of 4g over 5 - 15 mins then infusion of 1g/hour for 24 hours
• After fit: infusion continued for 24h after last fit

Question 122

Describe screening and prevention of eclampsia

Answer 122

• There is NO screening test for pre-eclampsia
• Doppler ultrasound uterine artery waveform analysis has been investigated with varying success
• This may be useful in screening women at risk of pre-eclampsia, but it is NOT useful in low-risk women
• Preventive interventions include low-dose aspirin (75 mg daily) modestly reduces the risk of pre-eclampsia in high-risk women

Question 123

What is further management of pre-eclampsia?

Answer 123

• Iatrogenic premature delivery is often required
• If < 34 weeks, IM corticosteroids should be given to the mother
• Delivery before term is usually by C-section
• These patients are usually at HIGH RISK of thromboembolism and should be given prophylactic SC heparin and given anti-thromboembolic stockings
• In spontaneous or induced labour (if clotting studies are normal), epidural anaesthesia is indicated as it helps control blood pressure
• Ergometrine should be AVOIDED as it significantly increases blood pressure
• Post-natally, blood pressure and proteinuria should resolve within 6 weeks
• If it fails to resolve, consider chronic hypertension or renal disease

Question 124

What is the MANAGEMENT of pre-eclampsia (NICE Guidelines)?

Answer 124

• Refer to table above
• Manage pregnancy in women with pre-eclampsia conservatively until 34 weeks
• Set maternal and foetal thresholds for elective birth before 34 weeks
• Write a plan for foetal monitoring during birth
• Offer birth to women with pre-eclampsia before 34 weeks after a course of corticosteroids if:
  
  • Severe hypertension develops which is refractory to treatment
  • Maternal or foetal indications as specified in the management plan
• Recommend birth in women with severe hypertension after 34 weeks when blood pressure is under control and a course of corticosteroids has been completed
• Offer birth to women with mild or moderate hypertension at 34-37 weeks depending on foetal and maternal condition
• Recommend birth within 24-48 hours for women with pre-eclampsia and mild-moderate hypertension after 37 weeks
• Anticonvulsants
  
  • Give IV magnesium sulphate if:
    
    • In critical care setting with severe hypertension or previous eclamptic fit
    • Severe hypertension and proteinuria
    • Symptoms (e.g. severe headache, visual disturbance, epigastric pain, liver tenderness)
  • Loading dose of 4 g should be given IV over 5 mins followed by an infusion of 1 g/hour for 24 hours

Question 125

What is Chronic Hypertension mainly due to?

Answer 125

• Essential hypertension is responsible for 90% of cases

- Renal causes are responsible for 80% of cases of secondary hypertension

Question 126

What are the causes of chronic hypertension?

Answer 126

• Idiopathic
• Essential hypertension
• Vascular disorders
• Renal artery stenosis
• Coarctation of the aorta
• Renal disease
• Polycystic disease

Question 127

What are the risks of pre-existing hypertension in pregnancy?

Answer 127

• Pre-eclampsia
• Abruption
• Heart failure
• Intracerebral haemorrhage

Question 128

What is the management of chronic hypertension?

Answer 128

• Mild cases (< 150/100 mm Hg)- don’t treate
  
  • Should be monitored to detect BP changes or pre-eclampsia features
  • Monitor for FGR by serial ultrasounds
• Antihypertensive medication pre-pregnancy can usually be stopped for the first half of pregnancy as there is a physiological reduction in BP
• ACE inhibitors, ARBs and atenolol should be discontinued (may cause teratogenicity and negative effects on foetal growth)
• If blood pressure is consistently > 150/100 mm Hg, offerantihypertensive medication
  
  • Preferred agents include:
    
    • Labetalol
    • Nifedipine
    • Methyldopa
  • Treatment to maintain BP < 160/80-100 mm Hg
• Delivery is usually offered around 39 weeks
• After delivery, maternal blood pressure often decreases but tends to increase again on the 3rd or 4th day postpartum
• Consider which drugs are safe with breastfeeding

Question 129

What is foetal growth restriction?

Answer 129

• failure of a foetus to achieve its genetic growth potential
• This usually results in a baby that is small for gestational age (SGA) meaning that they are below the 10th centile for its gestation
• IMPORTANT
  
  • Most SGA foetuses are constitutionally small
  • FGR suggests that there is a pathological process leading to restricted growth

Question 130

What are the causes of FGR?

Answer 130

• Reduced foetal growth potential
  
  • Aneuploidies
  • Single gene defects (e.g. Seckel’s syndrome)
  • Structural abnormalities (e.g. renal agenesis)
  • Intrauterine infections (e.g. CMV, toxoplasmosis)
• Reduced foetal growth support
  
  • Maternal factors
    
    • Undernutrition (e.g. poverty)
    • Maternal hypoxia (e.g. living at altitude, cyanotic heart disease)
    • Drugs (e.g. alcohol, cigarettes, cocaine)
      
      • Smoking increases the amount of carboxyhaemoglobin in the maternal circulation thereby reducing the amount of oxygen available to the foetus
• Placental factors
  
  • Reduced uteroplacental perfusion (e.g. inadequate trophoblast invasion, sickle cell disease, multiple gestation)
  • Reduced fetoplacental perfusion (e.g. single umbilical artery, twin-to-twin transfusion syndrome)

Question 131

What is the pathophysiology of FGR?

Answer 131

• FGR is often classified as symmetrical or asymmetrical
• Symmetrical
  
  • Directly impair foetal growth (e.g. chromosomal disorders and foetal infections)
• Asymmetrical
  
  • Ureteroplacental insufficiency –> decreased oxygen to the foetus and reduced carbon dioxide removal
  • When the foetus is hypoxic, more of the well-oxygenated blood from the umbilical vein will go via the ductus venosus, meaning that the liver will receive little oxygenated blood
  • This results in an asymmetrical foetus with relative brain sparing and reduced abdominal girth and skin thickness
  • Vasoconstriction in the foetal kidneys results in impaired urine production and oligohydramnios
• Chronic foetal hypoxia in FGR can lead to foetal acidaemia (both respiratory and metabolic) which can lead to intrauterine death if prolonged

Question 132

What is the management of FGR?

Answer 132

• Detection of SGA consists of TWO elements:
  
  • Accurate assessment of gestational age
  • Recognition of foetal smallness
• Early measurement of foetal CRL (< 13+6 weeks) or head circumference (13+6-20 weeks) is the method of choice for confirming gestational age
• The most precise way of assessing foetal growth is by ultrasound biometry (biparietal diameter, head circumference, abdominal circumference and femur length) serially at set intervals (usually 4 weeks)
  
  • Serial measurements tend to only be performed for at-risk pregnancies
• Once SGA is diagnosed, the next step is to clarify whether the foetus is constitutionally small or whether it is FGR
• There are no widely accepted treatments for FGR due to uteroplacental insufficiency (but smoking, alcohol and drugs should be stopped)
• Low-dose aspirin may have some role in preventing FGR in high-risk pregnancies but has no effect once it has been established

Question 133

What are the risk factors for FGR?

Answer 133

• Multiple pregnancies
• History of FGR in previous pregnancy
• Current heavy smokers
• Current drug users
• Women with underlying medical disorders
  
  • Hypertension
  • Diabetes
  • Cyanotic heart disease
  • Antiphospholipid syndrome
• Pregnancies where symphysis-fundal height is less than expected

Question 134

What is the prognosis of FGR?

Answer 134

• For survivors of FGR due to uteroplacental insufficiency, prognosis is good and most infants show catch-up growth after delivery
• There is an association between FGR and adult-onset hypertension and diabetes

Question 135

What are symptoms of pre-eclampsia?

Answer 135

• Severe headache
• Visual disturbance (e.g. burring, flashing)
• Severe pain just below the ribs
• Vomiting
• Sudden swelling of the face, hands or feet

Question 136

What are NICE guidelines for management for pregnancy with chronic hypertension at the timing of birth and for the assessment of proteinuria?

Answer 136

Timing of Birth
- If there’s chronic hypertension and BP < 160/110 mm Hg do NOT offer delivery before 37 weeks

• Offer birth if refractory severe chronic hypertension (after corticosteroids if needed)
• Monitor blood pressure in women with chronic hypertension who have given birth and consider changing antihypertensive medication

Assessment of Proteinuria
- Use an automated reagent-strip reading device or a spot urinary protein: creatinine ratio

• If a result of 1+ or more is obtained, use spot urinary protein: creatinine ratio or 24-hour urine collection to quantify proteinuria
• Diagnose significant proteinuria if the urinary protein: creatinine ratio is > 30 mg/mmol or a validated 24-hour urine collection shows > 300 mg protein

Question 137

Describe postnatal investigation, monitoring and treatment for gestational hypertension

Answer 137

• In women with gestational hypertension who have given birth, measure blood pressure:
  
  • Daily for the first 2 days
  • At least once between days 3 and 5
  • As indicated if antihypertensive treatment changes after birth
• In women with gestational hypertension who have given birth:
  
  • Continue use of antenatal antihypertensive treatment
  • Consider reducing antihypertensive treatment if their blood pressure falls < 140/90 mm Hg
  • Reduce antihypertensive treatment if their blood pressure falls < 130/80 mm Hg
• Consider reducing antihypertensive treatment if the blood pressure falls
• If the woman was taking methyldopa during pregnancy, stop within 2 days
• Write a care plan for women with gestational hypertension who have given birth and are being transferred to community care
• Offer women who have had gestational hypertension and remain on antihypertensive treatment 2 weeks after transfer to community care, a medical review

Question 138

Describe postnatal investigation, monitoring and treatment for pre-eclampsia

Answer 138

• Monitor blood pressure:
  
  • At least 4/day if inpatient
  • At least once between day 3 to 5
  • On alternate days until abnormal BP becomes normal on days 3-5
• Pre-eclampsia woman not on antihypertensives, start treatment if BP > 150/100 mm Hg
• Ask about severe headache and epigastric pain every time BP is measured
• Pre-eclampsia woman who have taken antihypertensive treatment and given birth:
  
  • Continue antenatal hypertensives
  • Consider reducing antihypertensive if BP < 140/90 mm Hg
  • Reduce antihypertensive treatment if BP < 130/80 mm Hg
• If a woman has taken methyldopa for her pre-eclampsia, stop within 2 days of birth
• Offer transfer to community care if all the following have been met:
  
  • No symptoms of pre-eclampsia
  • Blood pressure < 149/99 mm Hg
  • Blood test results are stable or improving
• Write a care plan including frequency of blood pressure monitoring, thresholds for reducing/stopping treatment, indications for referral and self-monitoring of symptoms
• Offer women who have pre-eclampsia and are still on antihypertensive treatment 2 weeks after transfer to community care a medical review

Question 139

Which foetal monitoring should be done in chronic hypertension?

Answer 139

• Ultrasound foetal growth
• Amniotic fluid volume assessment
• Umbilical artery Doppler velocimetry
• Between 28-30 weeks and 32-34 weeks
• Only do CTG if activity is abnormal

Question 140

Describe foetal monitoring in mild or moderate gestational hypertension

Answer 140

• Carry out ultrasound foetal growth, amniotic fluid volume assessment and umbilical artery Doppler velocimetry if diagnosis is confirmed at < 34 weeks
• Only do CTG if activity is abnormal

Question 141

Describe foetal monitoring in Severe gestational hypertension or pre-eclampsia

Answer 141

• Do CTG at time of diagnosis
  
  • If normal, do not repeat more than weekly
  • Repeat CTG if:
    
    • Woman report change in foetal movement
    • Vaginal bleeding
    • Abdominal pain
    • Deterioration in maternal condition
• If conservative management planned, carry out:
  
  • Ultrasound foetal growth and amniotic fluid volume assessment
  • Umbilical artery Doppler velocimetry

Question 142

What foetal monitoring in Women at high risk of pre-eclampsia should be done and when?

When would you repeat this foetal monitoring?

Answer 142

• Carry out ultrasound foetal growth, amniotic fluid volume assessment and umbilical artery Doppler velocimetry starting at 28-30 weeks
• Repeat 4 weeks later in women with:
  • Severe pre-eclampsia
  • Pre-eclampsia that needed birth before 34 weeks
  • Pre-eclampsia with an SGA baby
  • Intrauterine death
  • Placental abruption

Question 143

Describe Blood pressure intrapartum care

Answer 143

• During labour, measure blood pressure:
  
  • Hourly if mild/moderate hypertension
  • Continually if severe hypertension
• Continue to use antenatal antihypertensive treatment during labour
• Do NOT routinely limit the duration of the second stage of labour:
  
  • In women with mild/moderate hypertension
  • If blood pressure is controlled within target ranges in women with severe hypertension
• Recommend operative birth in the second stage of labour in women with severe hypertension whose hypertension has not responded to initial treatment

Question 144

What is the Medical management of severe hypertension or severe pre-eclampsia in a critical care setting?

Answer 144

• IV magnesium sulphate
• Consider IV magnesium sulphate for women with severe pre-eclampsia in a critical care setting if birth is planned within 24 hours
• Dosing of magnesium sulphate
  
  • Loading IV dose of 4 g over 5 mins, followed by an infusion of 1 g/hour for 24 hours
  • Recurrent seizures should be treated with a further dose of 2-4 g over 5 mins
• Treat women with severe hypertension in a critical care setting during pregnancy or after birth immediately with one of the following:
  
  • Labetalol (oral or IV)
  • Hydralazine (IV)
  • Nifedipine (oral)
• Monitor response to treatment:
  
  • To ensure blood pressure falls
  • To identify adverse effects
  • To modify treatment according to response
• Use corticosteroids (betamethasone) if delivery is likely < 36 weeks
  
  • NOTE: do NOT use corticosteroids in HELLP syndrome

Question 145

What are features of severe pre-eclampsia?

Answer 145

• Severe hypertension and proteinuria
• Mild or moderate hypertension with one or more of the following:
  • Severe headache
  • Visual disturbance
  • Severe pain just below the ribs
  • Papilloedema
  • Signs of clonus
  • Liver tenderness
  • HELLP syndrome
  • Platelet count falling below 100 x 109/L
  • Abnormal liver enzymes

Question 146

Describe breastfeeding in women with severe pre-eclampsia

Answer 146

• Avoid diuretics if breastfeeding or expressing milk
• NOT recommended when breastfeeding:
  
  • ARBs
  • ACE inhibitors (except enalapril and captopril)
  • Amlodipine
• Drugs that are ok: labetalol, nifedipine, enalapril, captopril, atenolol, metoprolol

Question 147

How does gestational hypertension and pre-eclampsia blood pressure in the future?

Answer 147

• Gestational hypertension and pre-eclampsia increase the risk of the mother developing hypertension later on
• Increased relative risk of kidney disease but the absolute risk is small if no proteinuria or hypertension at the 6-8 week review
• If a woman had gestational hypertension their risk in future pregnancies of:
  
  • Gestational hypertension = 16-47%
  • Pre-eclampsia = 2-7%
• If a woman had pre-eclampsia their risk in future pregnancies of:
  
  • Gestational hypertension = 13-53%
  • Pre-eclampsia = 16% (higher if they had severe pre-eclampsia, HELLP syndrome etc.)

Question 148

What is the Puerperium?

Answer 148

• 6-week period following completion of the 3rd stage of labour

Question 149

What is Uterine involution?

Answer 149

• Involution is the process by which the post-partum uterus (1 kg) returns to its pre-pregnancy stage (< 100 g)
• The fundus goes from lying 12 cm above the pubic symphysis to becoming no longer palpable above the symphysis
• Involution occurs due to autolysis (muscle cells diminish in size due to enzymatic degradation of cytoplasm)
• This makes no difference to number of muscle cells
• Excess protein is absorbed and excreted in the urine
• Autolysis is accelerated by the release of oxytocin in women who are breastfeeding
• A delay of involution with no other symptoms is NOT concerning

Question 150

What are signs of delayed involution?

Answer 150

• Artefact
• Full bladder
• Loaded rectum
• Retained products of conception (or clots)
• Uterine infection
• Fibroids
• Broad ligament haematoma

Question 151

What genital tract changes occur during the Puerperium?

Answer 151

• After delivery, the cervix can accommodate 2 fingers
• After 1 week, it will barely accommodate 1 finger
• After 2 weeks, the internal os should be closed
• NOTE: the external os can remain open permanently, giving a ‘funnel-shape’ to the parous cervix
• Assessing the postpartum cervix is important to diagnose retained products of conception

Question 152

What is lochia?

Answer 152

• This is blood-stained uterine discharge comprising of blood and necrotic decidua
• Only the top layer of decidua is sloughed off

Question 153

What are the three types of lochia?

Answer 153

• Lochia Rubra - red coloured during the first few days after delivery (gradually changes to pink)
• Lochia Serosa - becomes serous by the 2nd week
• Lochia Alba - scanty yellow-white discharge lasting for 1 month

Question 154

Describe perineal tear after normal birth

Answer 154

• 80% complain of pain for the first 3 days after delivery
• 25% complain of pain at 10 days after delivery
• Local cooling and topical anaesthetics (e.g. 5% lignocaine) provide short-term symptomatic relief
• Regular paracetamol can offer effective analgesia
• Diclofenac may also be added
• Avoid codeine (causes constipation in mothers and may cause drowsiness in breastfed babies)
• The perineum should be kept clean using tap water only and sanitary pads should be changed frequently
• Safetynet about signs of infection (e.g. swelling, discharge, redness, fever)
• Swabs for culture should be taken if infection is suspected and antibiotics should be started
• Collections of pus should be drained
• Spontaneous opening of repaired perineal tears and episiotomies is usually due to infection
• Surgery can only be performed if there is no infection present

Question 155

Describe bladder function after normal birth

Answer 155

• Voiding difficulty and overdistension of the bladder are not uncommon
• Especially if regional anaesthesia has been used (bladder may take up to 8 hours to regain normal sensation after epidural anaesthesia)
• During this time, around 1 L of urine may be produced
• This can damage the detrusor, leading to a hypocontractile bladder
• This can lead to overflow incontinence
• NOTE: a distended bladder may cause an increase in the height of the fundus

Question 156

Why else can mothers experience increased post-partum urine production?

Answer 156

• Fluid loading before epidural analgesia
• Antidiuretic effect of high concentrations of oxytocin
• Increased postpartum diuresis
• Increased fluid intake by breastfeeding mothers
• NOTE: therefore, fluid balance can be difficult to monitor

Question 157

What are causes of dysuria in mothers who have just given birth?

Answer 157

• periurethral oedema
• Prolapsed haemorrhoids
• Anal fissures
• Abdominal wound haematoma
• Stool impaction o the rectum

Question 158

When is the best time to assess bladder function postpartum?

Answer 158

• A formal assessment of bladder function is best made 6 hours postnatally (at least 300 mL of urine should have been passed)
• If, after another attempt, little or no urine has been passed - a small intermittent catheter should be inserted
  • This should drain < 150 mL
  • If > 1 L is drained, an indwelling catheter is left for 48 hours to allow periurethral swelling to settle
  • To minimise the risk of overdistension in women who have had spinal anaesthesia, a urinary catheter is left in the bladder for at least 12 hours until the woman is mobile

Question 159

Why should incontinence be investigated (especially in early puerperium)?

Answer 159

• Urinary stress incontinence is RARELY a problem in the early puerperium
• So, any incontinence should be investigated to exclude:
  • Vesicovaginal fistula
  • Urethrovaginal fistula
  • Uterovaginal fistula

Question 160

Describe bowel function in puerperium

Answer 160

• Constipation is a COMMON problem in early puerperium
• Factors contributing to this include:
  
  • Interruption of a normal diet
  • Intrapartum dehydration
  • Opiate use
• Advise adequate fluid intake and increase in fibre intake
• Constipation may also be due to fear of evacuation due to pain from a sutured perineum, prolapsed haemorrhoids or anal fissures
• Avoidance of constipation is very important in women with 3rd or 4th degree perineal tears
• These women should receive lactulose and ispaghula husk (Fybogel) or methylcellulose immediately after the repair, for a period of 2 weeks
• Consider a fistula as a cause of anal incontinence in the postpartum period (around 50% of small fistulae will close spontaneously over 6 weeks)

Question 161

How do pelvic floor exercises affect bowel function in puerperium?

Answer 161

• Although widely believed, there is no solid evidence suggesting that antenatal pelvic floor exercises prevent incontinence or prolapse
• Women are usually taught postnatal exercises to cultivate a feeling of pelvic floor awareness

Question 162

Describe recovery from Caesarean Section

Answer 162

• C-section has a lower risk of pelvic floor problems but has a HIGHER RISK of:
  
  • Infection
  • Anaemia
  • Thromboembolism
• A sterile dressing is placed in theatre but will be removed after 24 hours
• The wound should be cleaned and dried daily with tap water
• ALL C-section women to have their Hb measured postop (ideally at day 2-3)
• Asymptomatic women with mild-moderate anaemia (Hb > 7 g/dL) can be treated with iron tablets
• Those with more SEVERE anaemia, are likely to need a blood transfusion
• Early mobilisation and good hydration is important in prevention of VTE
• 1-6 weeks of LMWH for those with multiple risk factors
• After the first few days, women should slowly increase their activity levels aided by oral analgesia as required

Question 163

Describe postnatal visits

Answer 163

• A midwife normally visits the mother and child 1-2 times in the first 10 days
• More frequent visits may be required in high-risk women or if an abnormality is detected
• At east visit, women should be asked specifically about their recovery
• Women should be provided with information about danger signs and given emotional support
• Anti-D immunoglobulin should be given to ALL RhD-negative mothers of RhD-positive babies
• The only routine test to perform at each postnatal visit in the first week is maternal blood pressure

Question 164

Apart from maternal blood pressure, what other tests should be done at postnatal visits if necessary?

Answer 164

• Signs of infection –> temperature, pulse and signs of uterine involution
• PPH –> pulse, blood pressure, signs of uterine involution
• Antenatal anaemia, complicated deliveries or PPH –> Hb should be checked on days 1-3 and iron offered if anaemic
• Women with Hb < 7 g/dL should be offered a transfusion

Question 165

What should women be asked 2 weeks postnatally?

Answer 165

• Asked about baby blues

Question 166

What exam happens 6 weeks postnatally?

Answer 166

• A formal postnatal exam by the GP
  
  • Assessment of woman’s mental and physical health and the progress of the baby
  • Direct questions should be asked about urinary, bowel and sexual function
  • Weight, urine analysis and blood pressure are checked

Question 167

How is pre-eclampsia managed in puerperium?

Answer 167

• Nearly 50% of all eclamptic fits happen postnatally
• It is also the highest risk time for fluid overload
• Those with severe pre-eclampsia should be managed for the first 24 hours in an HDU until their BP is controlled and they achieve good diuresis
• Those with mild or moderate pre-eclampsia are managed on a postnatal ward until stable
• They should continue antenatally prescribed antihypertensives with the aim of keeping BP < 150/100 mm Hg
  
  • Labetalol and slow-release nifedipine are good options
  • Usually needed for 1-2 weeks postnatally
  • A BP should be measured at home every 2 days and the dosage should be halved when BP < 140/90 mm Hg
• Those still on antihypertensives at 6 weeks should be referred to specialists

Question 168

What is secondary post-partum haemorrhage?

Answer 168

• DEFINITION: fresh bleeding from the genital tract between 24 hours and 6 weeks after delivery
• MOST COMMON time for secondary PPH is between days 7-14

Question 169

What are the causes of secondary post-partum haemorrhage?

Answer 169

• Endometritis - lower abdominal pain and a tender uterus with a closed internal os
• Retained products of conception - crampy lower abdominal pain, a uterus larger than appropriate, open internal os and a history of a prolonged 3rd stage of labour
• Both may have signs and symptoms of infection (e.g. fever, pungent lochia, uterine tenderness)

Question 170

If post-partum bleeding is heavy, what may mothers need?

Answer 170

• IV fluids or blood
• Strong oxytocics (e.g. ergometrine)
• Uterine evacuation
• Antibiotics (if placental tissue is found)
• NOTE: If there is NO clear diagnosis of PPH, expectant management with empirical antibiotics is usually used

Question 171

Apart from endometritis and retained products of conception, what other causes of secondary PPH are there?

Answer 171

• Hormonal contraception
• Bleeding disorders (e.g. von Willebrand disease)
• Choriocarcinoma (RARE)

Question 172

What is obstetric palsy?

Answer 172

• AKA traumatic neuritis

- Motor and/or sensory neuropathy in lower limbs following delivery

Question 173

What are presenting features of obstetric palsy?

Answer 173

• Sciatic pain
• Foot-drop
• Paraesthesia
• Hypoaesthesia
• Muscle wasting

Question 174

What is obstetric palsy caused by?

Answer 174

• Caused by proximal nerve damage as the lumbosacral plexus and nerve tracks are stretched and compressed by the foetal head
• Almost always associated with prolonged or obstructed labour
• It is now RARE, thanks to modern labour management
• If obstetric paralysis occurs after normal labour, consider epidural complications and herniation of the lumbosacral discs

Question 175

What is symphysis pubis diastasis?

Answer 175

• This is spontaneous separation of the symphysis pubis

- Associated with forceps delivery, rapid second stage of labour or severe abduction of the thighs during delivery

Question 176

What are the presenting features of symphysis pubis diastasis?

Answer 176

• Symphyseal pain aggravated by weight-bearing and walking
• Waddling gait
• Pubic tenderness
• Palpable interpubic gap

Question 177

What is the management of symphysis pubis diastasis?

Answer 177

• bed rest, anti-inflammatory agents, physiotherapy and pelvic corset

Question 178

Describe thromboembolism in puerperium

Answer 178

• Those at risk should be given prophylactic heparin injections
• If DVT or PE are suspected, full anticoagulant therapy should be initiated
• Lower limb compression ultrasound and/or lung scan should be carried out within 24-48 hours

Question 179

What is puerperal pyrexia?

Answer 179

• Temperature > 38 degrees on any 2 of the first 10 days postpartum, exclusive of the first 24 hours
• Mildly elevated temperature is not uncommon in the first 24 hours
• However, if this is associated with tachycardia, it warrants investigation
• If a women develops a fever after C-section, it is much more likely to be infection
• Common sites of puerperal pyrexia: chest, throat, breasts, urinary tract, pelvic organs, Caesarean scar, perineal wounds

Question 180

Describe chest complications in puerperium

Answer 180

• Most likely to appear within the first 24 hours (particularly after general anaesthesia)
• Atelectasis may be associated with a fever and can be prevented with early and regular chest physiotherapy
• Aspiration pneumonia (Mendelson’s syndrome) must be suspected if there is a spiking temperature associated with wheezing, dyspnoea or evidence of hypoxia following general anaesthetic

Question 181

What is puerperal sepsis?

Answer 181

• Genital tract infection following delivery

Question 182

What is the aetiology of puerperal sepsis?

Answer 182

• Mixed flora of low virulence normally colonises the vagina
• Puerperal infection is usually polymicrobial and involve contaminants from the bowel
• Placental separation exposes a large raw area (like an open wound)
• Vaginal delivery is almost inevitably going to cause some lacerations in the genital tract

Question 183

What organisms are commonly associated with puerperal genital infection?

Answer 183

Aerobes

• Gram-positive
  
  • beta haemolytic streptococcus, groups A, B, D
  • Staphylococcus epidermidis and S. aureus
• Gram negative
  
  • Escherichia coli
  • Haemophilus influenzae
  • Klebsiella pneumoniae
  • Psuedomonas aeruginosa

Anaerobes
- Peptococcus sp

• Chlamydia trachomatis

Question 184

How do you prevent puerperal infection?

Answer 184

• Increased awareness of hygiene
• Good surgical approach
• Use of aseptic techniques
• C-section patients should receive prophylactic antibiotics
  
  • A single intraoperative dose of antibiotics (co-amoxiclav or cephalosporin with metronidazole) is given before the skin incision

Question 185

How does puerperal infection spread?

Answer 185

• Ascending infection from the lower genital tract or primary infection of the placental site may spread via the Fallopian tubes to the ovaries (causing salpingo-oophoritis and pelvic peritonitis)
  
  • This could progress to generalised peritonitis and the development of a pelvic abscess
• Infection may spread directly into the myometrium and parametrium
  
  • Causes endometritis and parametritis (aka pelvic cellulitis)
  • Pelvic peritonitis and abscess may occur
• Infection may spread from distant sites via the lymphatics and blood vessels
  
  • This can cause septic thrombophlebitis, pulmonary infections or generalised septicaemia and endotoxic shock

Question 186

What are symptoms of puerperal infection?

Answer 186

• Malaise, headache, fever, rigors
• Abdominal discomfort
• Vomiting and diarrhoea
• Offensive lochia
• Secondary PPH

Question 187

What are signs of puerperal infection?

Answer 187

• Pyrexia and tachycardia
• Uterus - boggy, tender and larger
• Infected wounds
• Peritonism
• Paralytic ileus
• Indurated adnexae (paramtritis)
• Bogginess in pelvis (abscess)

Question 188

What is the management of puerperal infection?

Answer 188

• Mild to moderate infections can be treated with broad-spectrum antibiotics (e.g. co-amoxiclav or cephalosporin + metronidazole)
• In SEVERE infections, the release of vasoactive mediators can lead to septic or endotoxic shock
  • Immediate high-dose, broad-spectrum antibiotics and IV fluid resuscitation should be given in an HDU

Question 189

Where can necrotising fasciitis arise from?
Which organism is usually identified?
What are signs?
What is its management?

Answer 189

• Necrotising fasciitis is rare but can arise from perineal tears, episiotomis and C-section wounds
  
  • Clostridium perfringens is usually identified
  • General signs of infection will be accompanied by extensive necrosis, crepitus and inflammation
  • Wide debridement of necrotic tissue under GA is absolutely essential to avoid mortality

Question 190

Describe puerperal psychiatric disorders

Answer 190

• The risk of bipolar disorders and severe depressive illness are greatly increased postpartum
• Women with previous mental health problems are at particular risk of recurrence during the antepartum and postpartum period
• Changes in hormone levels are likely to contribute (e.g. progesterone)
• NOTE: depression may be a manifestation of postpartum hypothyroidism

Question 191

What are the Pinks?

Answer 191

• First 24-48 hours

- Elevated mood, a feeling of excitement, overactivity and difficulty sleeping

Question 192

What are the Blues?

Answer 192

• Up to 80% experience postnatal blues in the first 2 weeks after delivery
• Features: fatigue, short temper, difficulty sleeping, depressed mood and tearfulness
• Spontaneous resolution in most cases

Question 193

What are abnormal features NOT consistent with baby blues?

Answer 193

• Panic attacks
• Episodes of low mood for a prolonged duration (> 2 weeks)
• Low self-esteem
• Guilt or hopelessness
• Thoughts of self-harm or suicide
• Mood changes that disrupt normal social functioning
• Biological symptoms (e.g. poor appetite)
• Change in affect

Question 194

What are screening questions for mental health problems during or after pregnancy? (at booking, and in the postnatal period (at least twice))

Answer 194

• During the past month, have you often felt down, depressed or hopeless?
• During the past month, have you often been bothered by having little interest or pleasure in doing things?
• Are these feelings something you need or want help with?

Question 195

Describe Postpartum (non-psychotic) Depressive Illness

Answer 195

• 10-15% will suffer some form of depression in the first year after delivery
• Without treatment, most women recover spontaneously within 3-6 months (but 1 in 10 will remain depressed at 1 year)
• Women with a history of severe depression are at higher risk
• The Edinburgh Postnatal Depression Scale is a screening technique
• ALL women should be asked about their mood at least twice in the postpartum period (ideally at 6 weeks and 3-4 months)
• Women at HIGH RISK should be under close surveillance by the specialist community psychiatric nurse

Question 196

How long does post-partum depressive illness occur for?

Answer 196

• Usually presents around 6 weeks with a gradual onset

- Therefore, 6-week postnatal check is ideal to pick this up

Question 197

What are symptoms of severe postnatal depressive disorder?

Answer 197

• Early-morning wakening
• Poor appetite
• Diurnal mood variation (worse in the morning)
• Low energy and libido
• Loss of enjoyment
• Lack of interest
• Impaired concentration
• Tearfulness
• Feelings of guilt and failure
• Anxiety
• Thoughts of self-harm/suicide
• Thoughts of harm to the baby

Question 198

What are risk factors for Postnatal Depressive Illness?

Answer 198

• Past history of psychiatric illness
• Depression during pregnancy
• Obstetric factors (e.g. C-section, neonatal loss)
• Social isolation and deprivation
• Poor relationships
• Recent adverse life events (e.g. bereavement)
• Severe postnatal blues

Question 199

What are complications of Postnatal Depressive Illness?

Answer 199

• Physical morbidity
• Suicide
• Damaged social attachment to infant
• Disrupted emotional development of infant
• Social/cognitive effects on child
• Marital breakdown
• Future mental health problems

Question 200

What is the management of severe postnatal affective disorders?

Answer 200

• Remedy of social factors
• Non-directive counselling
• Interpersonal psychotherapy
• CBT
• Drug therapy
  
  • Usually TCAs and SSRIs
• Encouragement to join a local postnatal group may prevent social isolation and limit depression

Question 201

What is Puerperal Psychosis?

Answer 201

• MOST COMMONLY presents on the 5th day postpartum
• In general, presents within 4 weeks
• Abrupt onset

Question 202

What are the risk factors of puerperal psychosis?

Answer 202

• Previous history of puerperal psychosis
• Previous history of severe non-postpartum depressive illness
• Family history of bipolar disorder/affective psychosis

Question 203

What are symptoms of puerperal psychosis?

Answer 203

• Restless agitation
• Insomnia
• Perplexity/confusion
• Fear/suspicion
• Delusions/hallucinations
• Failure to eat and drink
• Thoughts of self-harm
• Depressive symptoms (guilt, hopelessness)
• Loss of insight

Question 204

What is the management of puerperal psychosis?

Answer 204

• Refer urgently to psychiatry
• Usually require admission (preferably to a mother-and-baby unit)
• Acute pharmacotherapy with neuroleptics (e.g. chlorpromazine, haloperidol)
• Treatment of mania with lithium carbonate
• Electroconvulsive therapy
• Antidepressants as 2nd line (takes 10-14 days to work)

Question 205

What is the prognosis of puerperal psychosis?

Answer 205

• Recover usually occurs over 4-6 weeks but treatment with antidepressants will be needed for at least 6 months
• Risk of recurrence in future pregnancy is 1 in 2
  • Women with previous puerperal psychosis should be considered for prophylactic lithium

Question 206

What is colostrum?

Answer 206

• Yellowish fluid secreted by the breast that can be expressed as early as the 16th week of pregnancy (replaced by milk during the second postpartum day)
• Colostrum has an important role in protection against infection

Question 207

What are the major constituents of breast milk?

Answer 207

• Lactose
• Protein (lactalbumin, lactoglobulin and caseinogen)
• Fat
• Water
• All vitamins except vitamin K

Question 208

What do prolactin and oxytocin do in breastfeeding?

Answer 208

• Prolactin stimulates milk synthesis and is essential for lactation
• Oxytocin causes contractions of the myoepithelial cells lying longitudinally along the lactiferous ducts causing expulsion of milk

Question 209

What is the rooting reflex?

Answer 209

• When the skin around the baby’s mouth is touched, the mouth begins to gape
• Babies should be fed on demand and left on the breast until feeding finishes spontaneously

Question 210

What are the advantages in breastfeeding?

Answer 210

• Readily available at the right temperature and ideal nutritional value
• Cheaper than formula feed
• Has a contraceptive effect associated with amenorrhoea
• Reduced necrotising enterocolitis risk in preterm babies
• Reduced childhood infective illness (especially gastroenteritis)
• Reduced atopic illness (e.g. eczema, asthma)
• Reduced juvenile diabetes
• Reduced childhood cancer (especially lymphoma)
• Reduced premenopausal breast cancer
• NOTE: HIV is transmitted in breastmilk, however, mothers in resource-limited settings are advised to take antiretrovirals and exclusively breastfeed as the risk of childhood mortality is higher if not breastfeeding

Question 211

How can lactation suppression occur?

Answer 211

• Fluid restriction

- Tight bra