Small for gestational age, HT disease of pregnancy, Maternal medicine

Question 1

What do we mean by small for gestational age?

Answer 1

● Estimated foetal weight less than the 10th centile.
○ Differs from intrauterine / foetal growth restriction (IUGR / FGR), which implies a
pathological restriction of full genetic growth potential (RCOG definition).
○ Severe SGA is defined at EFW less than 3rd centile.

Question 2

How can we measure foetal size?

Answer 2

Surveillance of foetal size can be performed with the following measurements:
1. Symphyseal fundal height (measured regularly at routine antenatal appointments
from 24+0 onwards).
2. Foetal abdominal circumference.
3. Femur length.
4. Head circumference / biparietal diameter.
5. Liquor volume / amniotic fluid index (normal = 5-25cm)

Question 3

What are the risk factors for small gestational age?

Answer 3

Maternal age >40
2. Smoker >11 cigarettes per day.
3. Maternal cocaine use in pregnancy.
4. Maternal daily vigorous exercise
5. Previous SGA baby
6. Previous stillbirth
7. Maternal SGA
8. Paternal SGA
9. Chronic hypertension
10. Diabetes with vascular disease
11. Renal impairment
12. Antiphospholipid syndrome
13. Nulliparity
14. Previous pre-eclampsia

Question 4

What are the investigations that we do for small gestational age?

Answer 4

● Routine monitoring:
○ First Line: SFH measurement
○ SFH is plotted on a customised growth chart.
■ Adjusted to maternal height, weight, parity and ethnicity.
○ Second Line: USS scan (see Foetal Measurement).
● Any single major risk factor:
○ Serial (2 weekly) USS and umbilical artery Doppler from 26-28 weeks.
● Any single SFH <10th centile or slow / static growth:
○ Serial USS and umbilical artery Doppler.

Question 5

What are some further investigations for SGA?

Answer 5

• umbilical artery doppler
• CMV and toxoplasmosis screening - indicated in severe SGA
• MCA Doppler

Question 6

Why do we use umbilical artery doppler for SGA?

Answer 6

• Normal low-resistance placenta allows continuous positive flow from foetus to placenta
  throughout the cardiac cycle (i.e. in systole and diastole).
• If end-diastolic flow is slowed / reversed, this suggests increased placental resistance, which
  implies placental compromise (for example due to pre-eclampsia) and is predictive of SGA.

Question 7

Why use MCA doppler for SGA?

Answer 7

• Measured in comparison to umbilical artery flow.
• Hypoxic foetus diverts blood flow to the brain to spare cerebral function - this increases MCA
  diastolic flow in relation to UA diastolic flow.
• MCA flow also increases in foetal anaemia.

Question 8

How do we manage SGA?

Answer 8

● RCOG recommends umbilical artery Doppler as the primary surveillance tool for an
SGA foetus.
● Current guidelines state, in general:
○ An SGA foetus should be delivered by caesarean section before 37 weeks
gestation.

Question 9

A woman is pregnant with her second baby - 20 weeks gestation – gush of fluid vaginally
Obstetrics think premature rupture of membranes
What do they do now?

Answer 9

Erythromycin for 10 days to reduce risk of chorioamnionitis

Question 10

A woman is pregnant with her second baby - 20 weeks gestation – gush of fluid vaginally
Obstetrics think premature rupture of membranes
What about steroids?

Answer 10

Too early for that
About 50% chance of delivery in the next 7 days

Question 11

When should we offer resuscitation?

Answer 11

1. Assess gestational age
2. Asess presence of non-modifiable risk factors
3. Assess modifiable Risk Factors

Question 12

How do we assess gestational age?

Answer 12

GA (weeks)
Extreme high risk: 22-23
High risk: 23-24
Moderate risk: 25-26

Question 13

Non - modifiable RFs for resuscitation- what increases gestational age (Decreases GA risk is opposite of these)

Answer 13

Gestational week: Beginning of week
Fetal growth: fetal growth restriction
Fetal sex: Male
Plurality: Multiple

Question 14

What are the modifiable risk factors for resuscitation which increase GA? Opposite for Decrease GA risk

Answer 14

Antenatal steroid: None
Setting for birth: Local Hospital

Question 15

Monitored maternal temperature & foetal growth
Nothing happens
Now 22 weeks gestation – should we offer resuscitation?
At Jessop survival sub 23 weeks is 30% at best – if you make it to the neonatal unit.
What intervention now to improve outcome?

Answer 15

12 mg betamethasone, 24 hours apart, hopefully up to 24 hours before delivery

Question 16

Monitored maternal temperature & foetal growth
Nothing happens
Now 22 weeks gestation
Given 12 mg betamethasone, 24 hours apart, hopefully up to 24 hours before delivery
Mother remains apyrexial
Foetal growth is faltering, down to second centile
Now 25 weeks gestation, estimated foetal weight 600 grams
What other assessments should they do?

Answer 16

Foetal blood flow – using Doppler
Absent end diastolic flow is a bad sign
Reversed end diastolic flow is even worse

Question 17

Monitored maternal temperature & foetal growth
Nothing happens
Now 22 weeks gestation
Given 12 mg betamethasone, 24 hours apart, hopefully up to 24 hours before delivery
Mother remains apyrexial
Foetal growth is faltering, down to second centile
Now 25 weeks gestation, estimated foetal weight 600 grams
Still pregnant however, now 28 weeks, estimated foetal weight 650 grams
Reversed end diastolic flow.
High concern about foetal demise
What should we do now?

Answer 17

Another course of steroids – only last 1 to 4 weeks
Intravenous MgSO4 – as neuroprotection 30% reduction in risk of cerebral palsy if given within 24 hours of birth

Question 18

What are the birth weight categories?

Answer 18

 1500g Very low birth weight
 1000g Extremely low birth weight
 750g Incredibly low birth weight

Question 19

What are the different types of Hypertensive disease of pregnancy?

Answer 19

Pregnancy-induced hypertension, Pre-eclampsia, Eclampsia, HELLP syndrome

Question 20

What is PIH?

Answer 20

PIH: new-onset hypertension, developing after 20 weeks gestation.

Question 21

What is Pre- eclampsia?

Answer 21

new-onset hypertension associated with proteinuria or systemic
features*, developing after 20 weeks gestation.
spiral arteries of the placenta form abnormally, leading to a high vascular resistance in these vessels.

Question 22

What is the presentation for PIH?

Answer 22

asymptomatic, headaches, blurred vision

Question 23

What is the presentation for pre- eclampsia?

Answer 23

asymptomatic, headaches, upper abdominal pain, blurred vision, reduced foetal
movements // brisk reflexes, systemic hypertension

Question 24

Classic triad of pre-eclampsia

Answer 24

Hypertension
Proteinuria
Oedema

Question 25

What is the pathophysiology of pre-eclampsia?

Answer 25

When the blastocyst implants on the endometrium, the outermost layer, called the syncytiotrophoblast, grows into the endometrium. It forms finger-like projections called chorionic villi. The chorionic villi contain fetal blood vessels.

Trophoblast invasion of the endometrium sends signals to the spiral arteries in that area of the endometrium, reducing their vascular resistance and making them more fragile. The blood flow to these arteries increases, and eventually they break down, leaving pools of blood called lacunae (lakes). Maternal blood flows from the uterine arteries, into these lacunae, and back out through the uterine veins. Lacunae form at around 20 weeks gestation.

When the process of forming lacunae is inadequate, the woman can develop pre-eclampsia. Pre-eclampsia is caused by high vascular resistance in the spiral arteries and poor perfusion of the placenta. This causes oxidative stress in the placenta, and the release of inflammatory chemicals into the systemic circulation, leading to systemic inflammation and impaired endothelial function in the blood vessels

SHORTEN PLEASE

Question 26

What are the RFs for pre- eclampsia?

Answer 26

High-risk factors are:

Pre-existing hypertension
Previous hypertension in pregnancy
Existing autoimmune conditions (e.g. systemic lupus erythematosus)
Diabetes
Chronic kidney disease

Moderate-risk factors are:

Older than 40
BMI > 35
More than 10 years since previous pregnancy
Multiple pregnancy
First pregnancy
Family history of pre-eclampsia

Question 27

Which women are offered aspirin from 12 weeks gestation for pre- eclampsia?

Answer 27

Women are offered aspirin from 12 weeks gestation until birth if they have one high-risk factor or more than one moderate-risk factors.

Question 28

What are the symptoms of pre-eclampsia?

Answer 28

Headache
Visual disturbance or blurriness
Nausea and vomiting
Upper abdominal or epigastric pain (this is due to liver swelling)
Oedema
Reduced urine output
Brisk reflexes

Question 29

What are the initial investigations for PIH and Pre- eclampsia?

Answer 29

○ blood pressure measurement (140/90mmHg, +30/+15 in pre-existing
hypertension)
○ urinalysis (protein 2+ on dipstick, >30mg/mmol protein-creatinine ratio)
○ sFLT : PlGF ratio (>85 is diagnostic)

Question 30

What are some further investigations for for PIH and Pre- eclampsia?

Answer 30

○ Bloods: FBC, U+E, LFT twice-weekly
○ Ultrasound scan: to assess foetal growth and AFI, 2-weekly
○ Umbilical Artery Doppler velocimetry: assess placental perfusion, 2-weekly
○ Cardiotocography: upon diagnosis, + if RFM, PV bleed, abdo pain, deterioration
○ Auscultation of foetal heart: offer at every appointment

Question 31

How do we make a diagnosis for pre-eclampsia?

Answer 31

The NICE guidelines (2019) advise a diagnosis can be made with a:

Systolic blood pressure above 140 mmHg
Diastolic blood pressure above 90 mmHg
PLUS any of:

Proteinuria (1+ or more on urine dipstick)
Organ dysfunction (e.g. raised creatinine, elevated liver enzymes, seizures, thrombocytopenia or haemolytic anaemia)
Placental dysfunction (e.g. fetal growth restriction or abnormal Doppler studies)

Proteinuria can be quantified using:

Urine protein:creatinine ratio (above 30mg/mmol is significant)
Urine albumin:creatinine ratio (above 8mg/mmol is significant)

Question 32

What is placental growth factor?

Answer 32

The NICE guidelines (2019) recommend the use of placental growth factor (PlGF) testing on one occasion during pregnancy in women suspected of having pre-eclampsia. Placental growth factor is a protein released by the placenta that functions to stimulate the development of new blood vessels. In pre-eclampsia, the levels of PlGF are low. NICE recommends using PlGF between 20 and 35 weeks gestation to rule-out pre-eclampsia.

Question 33

What is the management for gestational HT without proteinuria?

Answer 33

Treating to aim for a blood pressure below 135/85 mmHg
Admission for women with a blood pressure above 160/110 mmHg
Urine dipstick testing at least weekly
Monitoring of blood tests weekly (full blood count, liver enzymes and renal profile)
Monitoring fetal growth by serial growth scans
PlGF testing on one occasion

Question 34

What is the management for PIH and pre-eclampsia?

Answer 34

Prevention: 75mg aspirin OD from 12/40 onwards.
● First Line: labetalol (beta-blocker)
● Second Line: nifedipine
● Third Line: methyldopa
● Plus: consider early delivery at 37 weeks
● Intravenous hydralazine may be used as an antihypertensive in critical care in severe pre-eclampsia or eclampsia
● IV magnesium sulphate is given during labour and in the 24 hours afterwards to prevent seizures
● Fluid restriction is used during labour in severe pre-eclampsia or eclampsia, to avoid fluid overload

Question 35

What is given to women having a premature birth?

Answer 35

Corticosteroids should be given to women having a premature birth to help mature the fetal lungs.

Blood pressure is monitored closely after delivery. Blood pressure will return to normal over time once the placenta is removed.

For medical treatment, NICE recommend after delivery switching to one or a combination of:

Enalapril (first-line)
Nifedipine or amlodipine (first-line in black African or Caribbean patients)
Labetolol or atenolol (third-line)

Question 36

What are one of the main complications of pre- eclampsia?

Answer 36

Eclampsia: Tonic-clonic seizures in presence of pre-eclampsia

Question 37

How do we manage Eclampsia?

Answer 37

intravenous magnesium sulphate, emergency delivery via
LSCS.

Question 38

What is HELLP syndrome?

Answer 38

syndrome of Haemolysis, Elevated Liver enzymes, Low Platelets.

Question 39

Investigations for HELLP?

Answer 39

○ blood pressure measurement (140/90mmHg, +30/+15 in pre-existing
hypertension)
○ urinalysis (protein 2+ on dipstick, >30mg/mmol protein-creatinine ratio)
○ sFLT : PlGF ratio (>85 is diagnostic)

Question 40

What is the management for HELLP syndrome?

Answer 40

Prevention: 75mg aspirin OD from 12/40 onwards.
● First Line: labetalol (beta-blocker)
● Second Line: nifedipine
● Third Line: methyldopa
● Plus: consider early delivery at 37 weeks
● Expedite delivery

Question 41

What is the diagnostic criteria for severe pre-eclampisa requiring urgent hospital admission

Answer 41

1. Systolic BP > 160mmHg
2. Severe headaches, visual scotomata, N+V, Oliguria, epigastric pain, pulmonary oedema
3. Rising creatinine, elevated liver enzymes, thrombocytopenia

Question 42

Pathophysiology of pre- eclampsia?

Answer 42

1. Defective remodelling of maternal spinal arteries - inadequate oxygenation of trophoblastic tissue > oxidative stress
   1a. Stressted trophopblast releases pro-inflamm cytokines + sFLT into maternal circulation
   1b. Pro-inflamm cytokines distrupt maternal endothelium - leads to systemic inflamm response and reduced blood flow to maternal organs
   1c. HT due to impaired renal blood flow and reduced eGFR a s well as elevated sFLT
   1d. Proteinuria arises from glomerular changes of basement membrane and podocytes
2. Defective remodelling results in placental hypoperfusion - inadequate nutrient deliver to foetus causing IUGR
3. Systemic features arise from maternal endothelial dysfunction and resulting vasodilation - leads to hypovolemic shock
   3a. Seizures thought to be due to cerebral vasospasm

Question 43

What is obstetric cholestasis? (Definition)

Answer 43

● Obstetric condition causing increased serum bile acids and hepatic dysfunction.

Question 44

What is the pathophysiology for obstetric cholestasis?

Answer 44

○ Oestrogen inhibits hepatic bile acid receptors in genetically susceptible women,
leading to impaired bile acid homeostasis.
● Leads to deposition of bile salts in various tissues including skin and placenta.
● Skin deposition leads to pruritus (itching).
● Placental deposition causes raised foetal bile acid levels - this can cause acute foetal
deterioration - thought to be either foetal arrhythmia / cardiomyopathy or placental
vasoconstriction

Question 45

What are the S + S of obstetric cholestasis/ presentation?

Answer 45

● Pruritus (sparing hands and face).
● Excoriations (scratch marks).

Question 46

What are the investigations for obstetric cholestasis?

Answer 46

● Serum bile acids (raised above 19 micromol/L)
● Liver function tests

Question 47

What is the management for obstetric cholestasis?

Answer 47

● First Line: emollient plus antihistamine
● Second Line: ursodeoxycholic acid
● Plus: consider expedited delivery
○ Dependent on serum bile acid concentration
○ For example: delivery at 35-36 weeks for women with peak bile acid
concentration >100 micromol/L due to increased stillbirth risk.

Question 48

What is the definition of Gestational Diabetes mellitus?

Answer 48

● Chronic hyperglycemia and insulin resistance due to pregnancy

Question 49

What are the risk factors for gestational diabetes?

Answer 49

Previous gestational diabetes
Previous macrosomic baby (≥ 4.5kg)
BMI > 30
Ethnic origin (black Caribbean, Middle Eastern and South Asian)
Family history of diabetes (first-degree relative)

Question 50

What should anyone with RFs for with gestational diabetes do?

Answer 50

Anyone with risk factors should be screened with an oral glucose tolerance test at 24 – 28 weeks gestation. Women with previous gestational diabetes also have an OGTT soon after the booking clinic

Question 51

What is the aetiology/ pathophysiology of gestational diabetes?

Answer 51

● In normal pregnancy, local and placental hormones stimulate peripheral insulin
resistance - the purpose of this is to spare glucose for delivery to the developing foetus.
● This is accompanied by lipolysis and gluconeogenesis, further increasing free fatty acid
and glucose levels.
● Hypertrophy and hyperplasia of pancreatic beta-cells occurs to protect maternal glucose
homeostasis.
● Failure of this protective mechanism due to beta-cell dysfunction, in combination with
insulin resistance, leads to GDM.

Question 52

What are maternal complications of gestational diabetes?

Answer 52

○ Pre-eclampsia
○ Chronic type 2 diabetes (60%)
○ Increased risk of cardiovascular disease

Question 53

What are the foetal complications of gestational diabetes?

Answer 53

○ Macrosomia, leading to shoulder dystocia
○ Neonatal hypoglycaemia (due to dependence on maternal hyperglycaemia
raising endogenous foetal insulin).
○ Childhood obesity (2x background risk).
○ Increased risk of metabolic syndrome and associated complications in later life
○ Large for dates fetus

Question 54

What are the risk factors for gestational diabetes?

Answer 54

● BMI > 30
● Previous macrosomia
● Previous GDM
● Family history of diabetes mellitus
● Ethnicity with high prevalence of diabetes
Previous gestational diabetes
Previous macrosomic baby (≥ 4.5kg)
BMI > 30
Ethnic origin (black Caribbean, Middle Eastern and South Asian)
Family history of diabetes (first-degree relative)

Question 55

How do we perform an Oral Glucose Tolerance Test?

Answer 55

An OGTT should be performed in the morning after a fast (they can drink plain water). The patient drinks a 75g glucose drink at the start of the test. The blood sugar level is measured before the sugar drink (fasting) and then at 2 hours.

Normal results are:

Fasting: < 5.6 mmol/l
At 2 hours: < 7.8 mmol/l
Results higher than these values are used to diagnose gestational diabetes.

Question 56

How do we diagnose women with gestational diabetes?

Answer 56

● Women with any one of the above risk factors should be screened for GDM at 24-28
weeks.
● Women with glycosuria detected at a routine antenatal appointment should be
screened at any time in their pregnancy.
● First Line: oral glucose tolerance test (OGTT)
○ Fasting blood glucose, followed by 75g carbohydrate drink, with a second blood
glucose test 2 hours later.

Question 57

Diagnostic criteria for gestational diabetes

Answer 57

● Diagnostic Criteria: 5678
○ Fasting plasma glucose > 5.6mmol/L or
○ 2 hour glucose > 7.8mmol/L

Question 58

What is the management for gestational diabetes?

Answer 58

● First Line: 2 week trial of diet, exercise and self-monitoring glucose levels
● Second Line: if not successful, metformin
● If FPG >7.0: start insulin immediately.
● Plus: extra growth scans at 28, 32, 36 weeks.

Question 59

What is the NICE management guidelines for gestational diabetes?

Answer 59

• Fasting glucose less than 7 mmol/l: trial of diet and exercise for 1-2 weeks, followed by metformin, then insulin
• Fasting glucose above 7 mmol/l: start insulin ± metformin
• Fasting glucose above 6 mmol/l plus macrosomia (or other complications): start insulin ± metformin
• Glibenclamide (a sulfonylurea) is suggested as an option for women who decline insulin or cannot tolerate metformin.

Question 60

What do women who need to monitor their blood sugar levels targets should be according to NICE?

Answer 60

Fasting: 5.3 mmol/l
1 hour post-meal: 7.8 mmol/l
2 hours post-meal: 6.4 mmol/l
Avoiding levels of 4 mmol/l or below

Question 61

What should women with pre-existing diabetes do when pregnant or before becoming pregnant?

Answer 61

They should take 5mg folic acid from preconception until 12 weeks gestation.

Question 62

What should women with existing type 1 and type 2 diabetes aim for with insulin levels?

Answer 62

Same target levels as with gestational diabetes
Women with type 2 diabetes are managed using metformin and insulin, and other oral diabetic medications should be stopped.

Question 63

When should retinopathy screening be performed?

Answer 63

hould be performed shortly after booking and at 28 weeks gestation. This involves referral to an ophthalmologist to check for diabetic retinopathy. Diabetes carries a risk of rapid progression of retinopathy, and interventions may be required.

Question 64

What does NICE advise for a planned delivery for women with pre-existing diabetes?

Answer 64

advise a planned delivery between 37 and 38 + 6 weeks for women with pre-existing diabetes. (Women with gestational diabetes can give birth up to 40 + 6).

Question 65

When is a sliding-scale insulin regime considered?

Answer 65

during labour for women with type 1 diabetes. A dextrose and insulin infusion is titrated to blood sugar levels, according to the local protocol. This is also considered for women with poorly controlled blood sugars with gestational or type 2 diabetes

Question 66

Postnatal diabetes

Answer 66

Diabetes improves immediately after birth. Women with gestational diabetes can stop their diabetic medications immediately after birth. They need follow up to test their fasting glucose after at least six weeks.

Question 67

What should women with existing diabetes do?

Answer 67

Women with existing diabetes should lower their insulin doses and be wary of hypoglycaemia in the postnatal period. The insulin sensitivity will increase after birth and with breastfeeding.

Question 68

What are babies of mothers with diabetes at risk of?

Answer 68

Neonatal hypoglycaemia
Polycythaemia (raised haemoglobin)
Jaundice (raised bilirubin)
Congenital heart disease
Cardiomyopathy

Question 69

What do babies need for diabetes?

Answer 69

Babies need close monitoring for neonatal hypoglycaemia, with regular blood glucose checks and frequent feeds. The aim is to maintain their blood sugar above 2 mmol/l, and if it falls below this, they may need IV dextrose of nasogastric feeding.