Abnormal Pregnancy and Labour Flashcards
(97 cards)
1
Q
What is the definition of prolonged pregnancy?
A
Any pregnancy that goes past 42 weeks - occurs in 10% of pregnancies
2
Q
What are the complications of a prolonged pregnancy?
A
- Foetal distress
- Meconium staining
- Perinatal death
3
Q
What are the indications of inducing labour?
A
General:
- Prolonged pregnancy (41-42 weeks)
- Pre-labour term rupture of membranes
Foetal:
- Foetal growth restriction
Maternal:
- Hypertension
- Diabetes
- Pre-eclampsia
4
Q
What are the ways in which labour can be induced?
A
- Membrane sweeps
- Pharmacological intervention
5
Q
What is a membrane sweep? When should it be offered?
A
Inserting a digit through the internal os, and sweeping the membrane. This can be quite painful for the mother. It helps release endogenous prostaglandins.
It is offered at 40-41 weeks to nulliparous women, and at 41 weeks for parous women.
6
Q
What is the first line pharmacological intervention to induce labour?
A
Vaginal prostaglandins
- Usually a pessary
- One dose, with a second after 6 hours
- There is a risk of hyperstimulation
7
Q
What is the second line medical intervention to induce labour?
A
Amniotomy
- Inserting a small amnihook into the vagina and rupturing the membranes
- Oxytocin infusion started with infusion if labour has not begun within 2 hours
8
Q
What are the complications of inducing labour?
A
- Failure, needing caesarean section
- Uterine hyperstimulation
- Cord prolapse
- Post partum haemorrhage
9
Q
What are the contraindications to inducing labour?
A
- Foetal compromise
- Abnormal lie
- Placenta praevia
- Pelvic obstruction
- Two previous caesarean sections
10
Q
What is the definition of an instrumental delivery?
A
The use of forceps or a ventouse to deliver a child
11
Q
What are the different instruments involved in instrumental delivery?
A
Forceps:
- Two blades that cup together to hold the head
- Can be fixed or rotational
Ventouse
- Suction cup that is metal or plastic
- Attaches to the child’s scalp
12
Q
What are the indications for instrumental delivery?
A
Inadequate progression through the second stage of labour:
- > 3 hours for nulliparous women
- > 2 hours for parous women
Maternal exhaustion, foetal distress and assisting breech deliveries are all also indications
13
Q
What are the conditions required for instrumental delivery?
A
- Mother is consented
- Head should be at or below the ischial spines
- Foetal head should not be abdominally palpable
- Cervix should be fully dilated
- Position of head is known
- Adequate analgesia should be given
- Mother should be catheterised
14
Q
What are the contraindications for the use of a ventouse?
A
- Face presentations
- Gestation of <34 weeks
- Active bleeding from scalp
15
Q
What are the complications of forceps delivery?
A
Maternal:
- Uterine, cervical, vaginal and perineal trauma
- Haemorrhage
Foetal:
- Bruising, nerve injury
- Skull and neck fractures
16
Q
What are the complications of a ventouse delivery?
A
Maternal:
- Vaginal or perineal trauma
- Haemorrhage
Foetal:
- Chignon (scalp swelling)
- Scalp lacerations
- Neonatal jaundice
- Cephalhaematoma (subperiosteal bleeding)
17
Q
How long does it take to recover from a caesarean section?
A
A mother may need a 3-4 day stay in the hospital after a caesarean section
18
Q
What are the risks of a caesarean section?
A
Maternal:
- Infection of wound/uterus
- VTE, bleeding
- Damage to ureter/bladder
- Later uterine rupture in pregnancy
- Placenta praevia, accreta, increta, percreta
Foetal:
- Respiratory difficulties
19
Q
What are the indications of an elective caesarean section?
A
Maternal:
- Severe pre-eclampsia
- > 2 previous caesarean sections
- Small pelvis
- Placenta praevia
Foetal:
- Position of foetus
- Restricted growth of child
- Twins or multiple births
20
Q
What are the indications of an emergency caesarean section?
A
Maternal:
- Failed induction of labour
- Slow progression of labour
- Haemorrhage
Foetal:
- Foetal distress
- Foetal hypoxia
21
Q
What is involved in the preparation for a caesarean section?
A
- Consent
- Blood tests: group and save
- Ant-acids and antiemetics
- Catheter inserted
- Spinal/epidural/general anaesthesia
22
Q
How do you perform a caesarean section?
A
The procedure takes 30-50 minutes
- Bed is tilted at 15 degrees to lift pressure of womb on vessels
- Horizontal incision made at the top of the pubic bone
- Cut through skin, subcutaneous tissue, rectus sheath, transversalis fascia, uterus
- Remove foetus and cut cord
- Injection of oxytocin to constrict uterus and remove placenta
- Suture uterus, transversalis fascia and skin back together
23
Q
What is the difference between a classical caesarean section and a lower segment caesarean section?
A
A classical caesarean section involves a longitudinal incision, and is indicated in a transverse lie, very preterm delivery or large lower segment fibroids.
A lower segment caesarean section is associated with lower risks post procedure and future pregnancies.
24
Q
What is a perineal tear?
A
Any damage to the perineum during child birth
25
How do you classify perineal tears?
Degrees:
- First: damage to the skin
- Second: damage to the skin and perineal muscle (episiotomy)
- Third: damage to the skin, perineal muscle and anal sphincter
- Fourth: damage to the skin, perineal muscle, anal sphincter and anal epithelium
26
How often do perineal tears occur?
In up to 70% of births
27
How are perineal tears managed?
- Sutured closed
- Local or general anaesthetic may be needed
- Some first degree tears need no sutures
- Third and fourth degree tears taken to theatre
28
What are the complications of caesarean section?
- Haemorrhage
- Fistula
- Superficial dyspareunia
- Scarring
- Infection
- Faecal incontinence
29
What is an episiotomy?
A surgical cut into the perineal muscle to assist in birth
30
What are the indications for an episiotomy?
- Rigid perineal muscle
- Facilitate instrumental delivery
- Shoulder dystocia
- Malpresentation
- Foetal distress
31
How is an episiotomy performed?
- Local anaesthetic given
- Right mediolateral cut is made at least 45 degrees
- Pressure placed on head to slow descent and reduce risk of episiotomy extension
32
How is an episiotomy repaired?
- Local anaesthetic
- Suture made at apex of cut
- Continuous locking suture along episiotomy
- Finer continuous suture for the superficial skin
33
What advice should be given after an episiotomy?
- Healing should take up to a month
- Ice pack is helpful in first 12 months
- Keep area clean and relatively dry
- Exposing to fresh air can help with healing
Call someone if:
- The scar swells or there is a discharge
- The stitches get more painful
34
What is shoulder dystocia?
When the anterior shoulder is stuck behind the pubic symphysis
35
How often does shoulder dystocia occur?
1 in 200 pregnancies
36
What are the risk factors for shoulder dystocia?
- Previous shoulder dystocia
- GDM, macrosomia, diabetes mellitus
- High maternal BMI
- Small mother
37
What are the complications of shoulder dystocia?
Maternal:
- Vaginal tear
- Primary postpartum haemorrhage
- Emotional impact
Foetal:
- Cerebral damage
- Brachial plexus injury
- Shoulder/arm fracture
- Death
38
How does brachial plexus injury present in a child?
An internal rotation of the arm and a flexion at the wrist. This is usually temporary, but can be permanent.
39
What is premature rupture of membranes?
This is rupturing of membranes that is before the due time. It can be pre-term (before 37 weeks) or pre-labour (before the onset of labour)
40
How often does PROM occur?
In 2% of pregnancies
41
What are the risk factors for PROM?
- Infection is the main cause (BV)
- Placental abruption
- Polyhydramnios
- Multiple pregnancy
42
What are the clinical features of PROM?
A history of a gush of clear fluid
43
How should a case of PROM be examined?
- General observations for signs of infections (pyrexia and tachycardia)
- Abdominal examination for lie and presentation (check for placental abruption)
- Speculum examination after lying supine for 40 minutes
44
How should a case of PROM be investigated?
- Urinalysis
- High vaginal swab
- FBC and CRP
- USS to assess liquor volume
- CTG to assess foetal wellbeing
45
What are the complications of PROM?
- Pre-term delivery
- Chorioamnionitis
- Cord prolapse
46
How is PROM managed?
If less than 24 weeks:
- Termination of pregnancy
If between 24 weeks and 34 weeks:
- Erythromycin for 10 days
- Corticosteroids
- Close monitoring for signs of infection
If between 34 weeks and 37 weeks:
- Consider corticosteroids
- Consider induction
If after 37 weeks:
- Induce labour
With any signs of infection:
- Delivery, no matter the gestation
47
What is pre-term delivery?
Any labour before 37 weeks gestation
48
How common is pre-term delivery?
8% of pregnancies
49
What are the risk factors associated with pre-term delivery?
Maternal:
- Age, alcohol and drug use
- Previous pre-term delivery
- STIs
- Medical disorders
- Cervical incompetence
Foetal:
- Multiple pregnancies
- Congenital abnormalities
50
What screening programmes exist for pre-term deliveries?
High risk women are those with:
- Previous pre-term delivery
- Recurrent cervical dilatation
- A second trimester termination of pregnancy
Screened by:
- Foetal fibronectin; raised result is a 4x risk of pre-term delivery. If negative, unlikely to deliver in the next 14 days
- Measure cervical length, with TVUSS
51
What are the clinical features of pre-term delivery?
- Abdominal pain
- Vaginal pain
- Can be asymptomatic
52
How should a suspected case of pre-term labour be examined?
- Assess lie and presentation
- Assess regularity of contractions
- Speculum examination
53
How should a suspected case of pre-term delivery be investigated?
- USS: assess cervical length, presentation and placental position
- Urinalysis
- Foetal fibronectin
- CTG
- HVS, MSU
54
How is pre-term labour managed?
Steroids:
- Offered if less than 34 weeks gestation
- Beclamethasone 2 doses STAT (within 24 hours)
- May take 48 hours to work
Tocolytics:
- May prolong pregnancy
- Atosiban and Nifedipine
Antibiotics:
- If signs of infection present
Delivery:
- Vaginal preferred
- managed as term
- Ventouse contra-indicated; forceps used if necessary
55
What is an ECV? What are the success rates and important statistics?
External cephalic version is turning a breech presentation before labour to a cephalic presentation.
50% will succeed, 7% of those that don't will turn themselves, and 3% of those that do will turn back.
56
What are the contraindications for ECV?
- Placental abruption
- Previous bleeding within 7 days
- Abnormal doppler or CTG
- Severe pre-eclampsia
- ROM
- Maternal decline
- Anything which means CS is needed (praevia, multiple)
- Oligohydramnios or polyhydramnios
- Previous CS
57
How is an ECV performed?
- Doppler and CTG done before
- Tocolytics given to calm uterus
- 4 attempts made within 10 minutes
- CTG done again to confirm foetal wellness
- Anti D given if needed
58
What are the risks of an ECV?
- Placental abruption
- Higher risk of CS
- Haemorrhage
- PROM
- Foetal bradycardia
59
What is the definition of a large for dates pregnancy?
Where the weight, length or head circumference lies above the 90th centile when corrected for gestational age, gender and ethnicity.
60
What are the risk factors for a large for dates pregnancy?
- Gestational diabetes or pre-existing DM
- Pregnancies above 40 weeks
- Excessive maternal weight gain
- Multiparity
- Congenital anomalies (hydrops foetalis)
- Use of antibiotics (hydrops foetalis)
61
What are the complications of a large for dates pregnancy?
- Shoulder dystocia
| - Higher risk of trauma to the perineum
62
How is a large for dates pregnancy managed?
Depending on cause, some antenatal interventions may be appropriate.
Delivery should aim for a vaginal birth, but if the baby is very large and the mother is worried and inconsolable, a caesarean section may be appropriate.
63
Describe foetal malpresentation
This occurs in approximately 3-4 percent of babies. While malpresentations are not uncommon antenatally, they only become a problem if they persist past 37+0 weeks.
64
Describe breech presentation
There are three types:
- Frank
- Flexed
- Footling
Pre-disposing factors for breech presentation includes:
- Fibroids
- Uterine abnormalities and surgery
- Multiple pregnancy
- 0 Prematurity
- Placenta praevia
- Oligohydramnios or polyhydramnios
65
How is breech managed antenatally?
Any suspected breech should be confirmed with ultrasound at 36 weeks. This scan should also do a full examination of the foetus.
There are three options:
- ECV (see flashcards)
- Caesarean section
- Breech vaginal birth
A large study showed a 3 percent increased risk of death and serious morbidity for breech vaginal births so the recommendation is to do a caesarean section. However, a small proportion of women still do a breech vaginal birth (choice or precipitous labour).
66
What are the pre-requisites for a vaginal breech delivery?
Feto-maternal
- Presentation should be extended or flexed
- The feet should not be below the buttocks
- No evidence of feto-pelvic disproportion
- Estimated foetal weight of <3500g
- No evidence of hyperextension of the foetal head
67
How is a vaginal breech delivery managed?
- Foetal wellbeing and progress should be carefully monitored
- Epidural analgaesia may be advantageous
- Foetal blood sampling from buttocks provides accurate acid-base status
- Experienced breech delivery doctor
68
What is the technique for managing a breech vaginal delivery?
Characterised by masterly inactivity - hands off - approach
Delivery of buttocks
- Will present anterior-posterior diameter
- Only after anterior buttock is born can an episiotomy be cut
Delivery of legs and lower body
- If flexed, will birth spontaneously
- If extended, may need Pinard's manoeuvre (a finger to flex at the knee and extend at the hip, anteriorly then posteriorly.
Delivery of shoulders
- Finger placed above shoulder to birth arms
- Loveset's manoeuvre copies the movements of 'rocking the boat'.
Delivery of the head
- Mauriceau-Smellie-Veit manoeuvre (downward traction then upward movement to birth the head)
- May need forceps
69
What are the complications of a vaginal breech delivery?
The main worry is the baby will get stuck lol. Need an expert obstetrician to minimise risks.
70
What other malpresentations (other than frank, flexed or footling? What is an unstable lie?
Transverse or oblique
There is risk of cord prolapse.
Risk factors:
- Multiparity
Management:
- Gentle version will usually restore cephalic presentation
- Caesarean section unless cephalic in early labour or no SROM.
Unstable lie:
- When the foetus reverts back to a breech presentation after version or,
- When the baby keeps changing from breech to normal
- They are managed depending on presentation at labour or caesarean section
71
Describe post-dates pregnancy
This is defined as a pregnancy that has extended beyond 42+0 weeks gestation. This affects a tenth of pregnancies and the aetiology is unknown.
Associations:
- Increased risk of stillbirth
- Increased risk of perinatal death
- Increased risk of prolonged labour
- Increased risk of caesarean section
72
How are post-dates births managed?
- Foetal surveillance
- Induction of labour (see flashcards)
- CTG performed
Immediate induction of labour must occur if:
- Reduced amniotic fluid on scan
- Foetal growth is reduced
- Reduced foetal movements
- CTG is not perfect
- Mother is hypertensive or suffers from a significant medical condition
73
What is oligohydramnios?
This is too little amniotic fluid, defined as an amniotic fluid index (AFI) of less than the 5th centile for gestation.
74
What are the causes of oligohydramnios?
Usually caused by too little production, due to a range of causes:
- Renal agenesis (US: no kidneys)
- Multicystic kidneys (US: enlarged kidneys with multiple cysts)
- Urinary tract abnormality (US)
- IUGR and placental insufficiency (reduced SFH, abnormal CTG, US)
- Maternal drugs (NSAIDs)
- Post dates pregnancy
It can also be caused by leakage, by:
- PPROM (diagnosed with speculum, pool of amniotic fluid on posterior blade)
75
What are the complications of oligohydramnios?
- Pulmonary hypoplasia
- Limb deformities
Prognosis:
- Depends on scale of oligohydramnios
- If renal agenesis, lethal
76
What is polyhydramnios?
Defined as excess amniotic fluid, with an amniotic fluid index (AFI) of above the 95th centile.
Presentation:
- Abdominal swelling and discomfort
- Increased SFH
77
What are the causes for polyhydramnios?
Maternal:
- Diabetes
- Placental causes
- Chorioangioma
- Arteriovenous fistula
Foetal:
- Multiple gestation
- Idiopathic
- Oesophageal atresia/trachea=oesophageal fistula
- Duodenal atresia
- Neuromuscular foetal condition (prevents swallowing)
- Anencephaly
78
What is the management of polyhydramnios?
Directed at establishing the cause, relieving the discomfort and assessing the risk of preterm labour due to uterine distension.
If due to GDM: correcting blood glucose should correct polyhydramnios
Twin to twin transfusion syndrome: rare but can be treated by:
- Amniodrainage
- Laser removal of anastomoses between foetal vessels
79
What is the importance of rhesus disease?
It is the most common association to haemolytic disease in the newborn
80
What is the aetiology of rhesus disease?
There are 40 antigens which comprise the rhesus system, the most important of which are C, D and E. They are coded for on chromosome 1.
It involves three key stages:
- Rhesus negative mother have a rhesus positive baby
- Foetal cells gain access to maternal circulation
- maternal antibodies must cross placenta to destruct foetal red cells
It does not affect the first pregnancy as the response is usually weak and is primarily IgM which does not cross the placenta. The second is far stronger and consists of IgG that can cross the placenta.
81
What is the epidemiology of rhesus disease?
15percent of women are D negative.
82
How is rhesus disease prevented?
- IM anti-D at 28 and 34 weeks
- IM anti-D within 72 hours of a sensitising event
- Anti-D of 250IU before 20 weeks, 500IU if after 20 weeks.
- Kleihauer test used to determine extent of foetal cells in the maternal circulation
Can now take free foetal DNA from maternal blood to assess blood group of children. Not routine in UK, but done in Denmark and the Netherlands.
Sensitising events:
- ECV
- Antepartum haemorrhage
83
What are the signs of foetal anaemia?
- Polyhydramnios
- Enlarged foetal heart
- Ascites and pericardial effusions
- Hyperdynamic foetal circulation
- Reduced foetal movements
- Abnormal CTG
84
How to manage rhesus disease in a sensitised woman
If father is D negative:
- No risk of rhesus positive so no chance of disease
If father is D positive:
- Closely monitor pregnancy
- Measure antibody levels every 2-4 weeks from booking
- Foetal transfusion if necessary
Foetal transfusion:
- Into umbilical vein at point of cord insertion
- Into intrahepatic vein
- Into peritoneal cavity
- Into foetal heart
85
What delivery considerations are there for rhesus disease?
- Neonatologist present to arrange transfusion if necessary
- Blood ready for delivery
- Cord blood taken at delivery for count, group and Coombs.
86
What is the definition of foetal growth restriction?
The failure of a foetus to achieve its full growth potential. Defined as small for gestational age at less than the 10th centile for its gestation. gender and race.
87
Are small for gestational age and foetal growth restriction the same thing?
No.
SGA: constitutionally small
FGR: pathological process restricting growth. Some FGR babies are not SGA.
88
What are some causes for small for gestational age?
- Congenital abnormalities
- Foetal infections
- Placental insufficiency
89
What is the aetiology of foetal growth restriction
Reduced potential
- Aneuploidies
- Single gene defects
- Structural abnormalities
- Intrauterine infections
Reduced growth support
- Maternal undernutrition (global major cause)
- Maternal hypoxia
- Maternal drug use (alcohol, cigarettes, cocaine)
- Reduced uteroplacental perfusion (inadequate trophoblast invasion (major cause - UK), sickle cell, multiple gestation)
- Reduced fetoplacental perfusion (single umbilical artery, TTTS)
90
Describe how inadequate trophoblast invasion leads to FGR
There is inadequate invasion of the spiral arteries, leading to reduced perfusion of the intracotyledon space. This leads to developmental abnormalities in the terminal villi and impaired transfer of oxygen and nutrients to the foetus.
This is a similar pathology to pre-eclampsia, hence the frequency of their co-presentation.
91
What is the pathophysiology of FGR?
FGR can be symmetrical or asymmetrical
Symmetrical:
- Direct impaired foetal growth (chromosomal, infections)
Asymmetrical:
- Uteroplacental insufficiency, with reduced oxygen transfer to the foetus.
92
Describe asymmetrical FGR
Usually due to a lack of oxygen delivery, there is a resultant drop in PO2 and a rise in PCO2.
This induces a chemoreceptor response in the foetal carotid bodies, resulting is vasodilation of the foetal brain, myocardium and adrenal glands, with vasoconstriction of the kidneys, liver, splanchnic vessels, limbs and subcutaneous tissues. This is called 'brain-sparing'.
This results in a foetus with relative brain sparing and reduced abdominal girth and skin thickness. The renal vasoconstriction leads to oligohydramnios. Foetal hypoxaemia leads to metabolic changes which reflect intrauterine starving.
Foetal blood sampling shows: reduced glucose, amino acids, thyroxine and insulin with increased catecholamines, corticosteroids (increased adrenal perfusion). There is also increased EPO and nucleated red blood cells.
93
How is FGR investigated?
Detection of SGA needs: accurate gestational aging and recognition of foetal smallness.
Gestational age: crown-lump length before 13+6, head circumference from 13+6 to 20. After 20 weeks, US biometry at time intervals.
When SGA diagnosis made, need to establish if it is normal or FGR. Comprehensive US should look for any anomalies to explain size.
Investigations: US, amniocentesis, foetal karyotyping
Features suspicious of FGR:
- Asymmetrical growth
- Small abdominal circumference
- Oligohydramnios
- High umbilical artery resistance
94
How is FGR managed
No unanimously accepted treatment.
Contributing factors stopped: drugs, alcohol, smoking
Prevention: low dose aspirin for high-risk, but not useful for established cases.
When severe:
- Bed rest in hospital
- Gain as much maturity for the foetus before delivery
- Intensive foetal surveillance
95
What is the prognosis of FGR?
Depends on cause.
For insufficiency, usually a good prognosis, most demonstrate 'catch-up growth'.
Link to adult-onset HTN and diabetes.
96
How is the FGR foetus surveyed?
Serial biometry and amniotic fluid volume measurements at 2 week intervals
Dynamic testing:
- Umbilical artery doppler analysis
- Foetal cardiotocography
97
What are some novel treatments for FGR
Sildenafil citrate acts like NO and can act to cause vasodilation is vessels responsive to NO. Spiral arteries have some responsiveness and trails are assessing the ability of sildenafil citrate to increase blood supply to the placenta.
