Obstetrics

Question 1

Increased AFP causes

Answer 1

Neural tube defects (meningocele, myelomeningocele and anencephaly)

Abdominal wall defects (omphalocele and gastroschisis)

Multiple pregnancy

Question 2

Decreased AFP causes

Answer 2

Down’s syndrome

Trisomy 18

Maternal diabetes mellitus

Question 3

Lifestyle advice to pregnant woman?

Answer 3

DO!!
- Folic acid 400mcg- before conception until 12 weeks-> reduce the risk of neural tube defects.
(higher requirements in certain conditions)
- 10 micrograms of vitamin D per day
- maternity rights and benefits. ask whether they work, usually safe but check for concerns -> The Health and Safety Executive
- beginning or continuing moderate exercise
- N&V- natural remedies (ginger and acupuncture on ‘p6’ point), promethazine (antihistamine) first line

DON’T
- No vitamin A supplementation (intake above 700 micrograms) = teratogenic.
- No drinking
- No smoking - NRT can be used, but not varenicline nor bupropion
- listeriosis - Avoid unpasteurised milk -> ripened soft cheeses (Camembert, Brie, blue-veined cheeses), pate or undercooked meat
- salmonella: avoid raw or partially cooked eggs and meat, especially poultry
- No Airtravel: women > 37 weeks singleton pregnancy , women with multiple pregnancies >32 weeks (VTE risk) (compression stockings if no CI)

Question 4

Antenatal care timetable

Answer 4

Uncomplicated pregnancy =7 visits, unless 1st pregnancy = 10 visits

8-12wks (ideally <10)
- Booking visit - lifestyle info, BP, urine dip & culture for asymptomatic bacteriuria, BMI
- Booking bloods - FBC, blood group, rhesus & other antibodies, haemoglobinopathies
- Hep B & syphillis (HIV offered)

10 - 13+6
- Early scan to confirm dates
- check for multiple pregnancy

11 - 13+6
- Down’s syndrome screening, nuchal scan

16
- Info on scan & blood results
- If Hb<11 - consider iron
- BP and urine dipstick

18 - 20+6
- Anomaly scan

28 weeks
- Second screen for anaemia and atypical red cell alloantibodies
- If Hb < 10.5 g/dl consider iron
- anti-D prophylaxis to rhesus -ve

34 weeks
- 2nd dose of anti-D prophylaxis
- Info: labour and birth plan

36
- Check presentation - offer external cephalic version if indicated
- info: on breast feeding, vitamin K, ‘baby-blues’

41
- labour plans and possibility of induction

Question 5

major causes of bleeding during each pregnancy trimester

Answer 5

1st trimester
Spontaneous abortion
Ectopic pregnancy
Hydatidiform mole

2nd trimester
Spontaneous abortion
Hydatidiform mole
Placental abruption

3rd trimester
Bloody show
Placental abruption
Placenta praevia (mother distressed)
Vasa praevia (Foetus distressed)

Question 6

Mastitis tx

Answer 6

only treat if
- systemically unwell
- nipple fissure
- symptoms do not improve after 12-24 hours of effective milk removal
- culture indicates infection

flucloxacillin for 10-14 days
Breastfeeding or expressing should continue during treatment

Question 7

CI to breastfeeding , drugs & other

Answer 7

The following drugs should be avoided:
antibiotics: ciprofloxacin, tetracycline, chloramphenicol, sulphonamides
psychiatric drugs: lithium, benzodiazepines
aspirin
carbimazole
amiodarone
sulfonylureas
methotrexate
cytotoxic drugs

galactosaemia
HIV (still feed in developing world)

Question 8

breech presentation mx

Answer 8

if < 36 weeks: many fetuses will turn spontaneously

if still breech at 36 weeks -external cephalic version (ECV)- offered from 36 weeks in nulliparous women and from 37 weeks in multiparous women

If the baby is still breech then - planned caesarean section or vaginal delivery

Question 9

absolute contraindications to ECV

Answer 9

where caesarean delivery is required

antepartum haemorrhage within the last 7 days

abnormal cardiotocography

major uterine anomaly

ruptured membranes

multiple pregnancy

Question 10

Caesarean sections categories

Answer 10

Cat 1 - immediate threat to the life of the mother or baby, w/in 30 minutes
(suspected uterine rupture, major placental abruption, cord prolapse, fetal hypoxia or persistent fetal bradycardia)

Category 2 - maternal or fetal compromise which is not immediately life-threatening, 75 minutes

Cat 3 - delivery is required, but mother and baby are stable

cat 4 - elective

Question 11

‘pre-terminal’ CTG features?

Answer 11

indicators for Emergency Caesarean section

terminal bradycardia- baseline fetal heart rate drops to below 100 beats per minute for more than 10 minutes

terminal decelerations- heart rate drops and does not recover for more than 3 minutes

Other changes (late decelerations, reduced variability, fetal tachycardia or bradycardia) are usually investigated with fetal scalp blood sampling and an ABG, looking for acidosis

Question 12

Management of chickenpox exposure in pregnancy,

post-exposure prophylaxis (PEP) & Management of chickenpox in pregnancy

Answer 12

PEP
any doubt about previously having chickenpox -> check varicella antibodies

1st line - oral aciclovir (or valaciclovir) is now the first choice at any stage - day 7 to day 14 after exposure

Chickenpox evelops
- oral aciclovir should be given if the pregnant women is ≥ 20 weeks & presents within 24 hours of onset of the rash
- if the woman is < 20 weeks the aciclovir should be ‘considered with caution’

Question 13

Down’s syndrome pregnancy screening

Answer 13

combined test is standard
- between 11 - 13+6 weeks
- ↑ HCG, ↓ PAPP-A, thickened nuchal translucency
(pregnancy-associated plasma protein A = PAPP-A)
(trisomy 18 (Edward syndrome) and 13 (Patau syndrome) give similar results but the hCG tends to lower)

if women book later in pregnancy the quadruple test should be offered between 15 - 20 weeks

Results:
‘lower chance’: 1 in 150 chance or more e.g. 1 in 300
‘higher chance’: 1 in 150 chance or less e.g. 1 in 100

Question 14

quadruple test results?

Answer 14

between 15 - 20 weeks, quadruple test: alpha-fetoprotein, unconjugated oestriol, human chorionic gonadotrophin and inhibin A

Down’s: low AFP & unconj estriol, high HCG & inhibin A (everything low, except HI)

Edward: low everything, normal inhibin

Neural tube: high AFP, low everything else

Results
‘lower chance’: 1 in 150 chance or more e.g. 1 in 300
‘higher chance’: 1 in 150 chance or less e.g. 1 in 100

Question 15

What should be monitored during magnesium sulphate tx?

Answer 15

urine output, reflexes, respiratory rate and oxygen saturations

respiratory depression can occur: calcium gluconate is the first-line treatment for magnesium sulphate induced respiratory depression

(sed to both prevent seizures in patients with severe pre-eclampsia and treat seizures once they develop - continue for 24 hours after last seizure or delivery)

Question 16

Causes of folic acid deficiency:

Answer 16

phenytoin
methotrexate
pregnancy
alcohol excess

Question 17

Prevention of neural tube defects (NTD) during pregnancy:

Answer 17

400mcg of folic acid before conception until the 12th week of pregnancy

5mg for:
- either partner has a NTD, previous pregnancy w NTD, a family history of a NTD
- taking antiepileptic drugs or has coeliac disease, diabetes, or thalassaemia trait.
- woman is obese ( [BMI] >=30 kg/m2 ).

Question 18

gestational diabetes dx

Answer 18

screening: oral glucose tolerance test (OGTT) - if pmh of GDM: asap after booking & 24-28 weeks. any of the other risk factors: OGTT at 24-28 weeks

Diagnostic:
fasting glucose is >= 5.6 mmol/L
2-hour glucose is >= 7.8 mmol/L

Question 19

Management of gestational diabetes

Answer 19

if the fasting plasma glucose level is < 7 mmol/l a trial of diet and exercise should be offered
- targets not met in 1-2 weeks-> metformin
- still not met-> insulin (short acting, not long acting)

If fasting glucose level is >= 7 mmol/l OR 6-6.9 & evidence of complications (macrosomia or hydramnios) - insulin should be started

Pre existing DM: stop oral hypoglycaemic agents except metformin, start insulin, folic acid 5 mg/day

Targets:
fasting: 5.3 - mmol/l

Question 20

Group B step mx

Answer 20

No screening

women who’ve had GBS detected in a previous pregnancy / previous baby with early- or late-onset GBS disease / preterm labour / women with a pyrexia during labour (>38ºC)

-> offered intrapartum antibiotic prophylaxis (IAP) - benzylpenicillin

Question 21

Pregnancy HTN mx

Answer 21

Hypertension in pregnancy: 140/90 0r 30/15 above booking reading

Pre-existing HTN - high BP before 20 wks
- stop ACEi before pregnancy, start labatalol

Gestational - after 20 wks, no proteinuria nor oedema
- oral labetalol, nifedipine/ hydralazine if asthmatic

Pre-eclampsia is above w proteinuria

• Women who are at high risk of developing pre-eclampsia should take aspirin 75mg od from 12 weeks until the birth of the baby.

Question 22

Bishop score

Answer 22

help assess whether induction of labour will be required
score of < 5 - labour is unlikely to start without induction
>= 8 - there is a high chance of spontaneous labour, or response to interventions made to induce labour

cervical position
0- posterior
1- intermediate
2 - anterior

cervical consistency
0 - firm
1 - intermediate
2 - soft

cervical effacement
0 - 0-30%
1 - 40-50%
2 - 60-70%
3 - 80%

cervical dilation
0 - <1cm
1 - 1-2cm
2 - 2-4cm
3 - >5cm

fetal station
0- -3
1 - -2
2 - -1,0
3 - +1,+2

Question 23

Induction of labour

Answer 23

membrane sweep (adjunct to induction of labour rather than an actual method of induction)

vaginal prostaglandin E2 (PGE2) - dinoprostone

oral prostaglandin E1 - misoprostol

maternal oxytocin infusion

amniotomy (‘breaking of waters’)

cervical ripening balloon

if the Bishop score is ≤ 6 - vaginal prostaglandins or oral misoprostol
If Bishop score is > 6 - amniotomy and an intravenous oxytocin infusion

Question 24

Intrahepatic cholestasis of pregnancy
mx

Answer 24

induction of labour at 37-38 weeks
ursodeoxycholic acid
vitamin K supplementation

Question 25

Labor stages

Answer 25

stage 1: from the onset of true labour to when the cervix is fully dilated (10-16 hours in primigravida)
- latent phase = 0-3 cm dilation, normally takes 6 hours
- active phase = 3-10 cm dilation, normally 1cm/hr
- less painful than 1st, lasts 1hr if longer consider Ventouse extraction, forceps delivery or caesarean section

stage 2: from full dilation to delivery of the fetus
- ‘passive second stage’ refers to the 2nd stage but in the absence of pushing (normal)
- active second stage’ refers to the active process of maternal pushing

stage 3: from delivery of fetus to when the placenta and membranes have been completely delivered

Head enters pelvis in occipito-lateral position. The head normally delivers in an occipito-anterior position.

Question 26

Placenta praevia ix

Answer 26

digital vaginal examination should not be performed before USS as it may provoke a severe haemorrhage

transvaginal ultrasound

Question 27

Placenta praevia mx

Answer 27

If low-lying placenta identified at the 20-week scan:
- rescan at 32 weeks -> if still present, scan every 2 weeks
- no need to limit activity or intercourse unless they bleed

final ultrasound at 36-37 weeks -elective caesarean section for grades III/IV between 37-38 weeks

if grade I then a trial of vaginal delivery may be offered

if a woman with known placenta praevia goes into labour- emergency c section

Question 28

placental abruption mx

Answer 28

Fetus alive and < 36 weeks
- fetal distress - immediate caesarean
- none - observe closely, steroids, no tocolysis

Fetus alive and > 36 weeks
- fetal distress: immediate caesarean
- no fetal distress: deliver vaginally

Question 29

post partum haemorrhage definition and causes

Answer 29

> 500ml after vaginal delivery

Primary (w/in 24hrs)
- Tone - uterine atony
- trauma - perineal teal
- tissue - retained placenta
- thrombin - clotting/ bleeding disorder

Secondary (24hrs - 6wks)
- due to retained placental tissue or endometriosis

Question 30

PPH mx

Answer 30

ABC
- lie woman flat
- catheterise - prevent bladder distension and monitor U/O

1st: mechanical - palpate the uterine fundus and rub it to stimulate contractions (‘rubbing up the fundus’)
2nd: IV Oxytocin (Syntocin) THEN Ergometrine unless the patient has hypertension
3rd: IM Carboprost (unless asthma)
5th: sublingual or Rectal Misoprostol
6th: intrauterine Balloon Tamponade (esp for uterine atony)
7th: B-Lynch suture, ligation of uterine/iliac arteries
8th: life-saving emergency hysterectomy

Question 31

Postnatal depression mx

Answer 31

(start within a month and typically peaks at 3 months)

Cognitive behavioural therapy
SSRI: sertraline/ paroxetine

(baby blues - 3-7 days following birth)

Question 32

Pre-eclampsia definition

Answer 32

new-onset blood pressure ≥ 140/90 mmHg after 20 weeks of pregnancy, AND 1 or more of the following:

Proteinuria

other organ involvement e.g. renal insufficiency (creatinine ≥ 90 umol/L), liver, neurological, haematological, uteroplacental dysfunction

Question 33

Prevention of hypertensive disease in pregnancy

Answer 33

women with the following should take aspirin 75-150mg daily from 12 weeks gestation until the birth
≥ 1 high risk factors
≥ 2 moderate factors

High
- CKD
- autoimmune disease: SLE, antiphopholipid
- DM
- chronic HTN
- HTN in previous pregnancy

Moderate
- primip
- >40yrs
- pregnancy interval of > 10 yrs
- BMI >35
- FH pre eclampsia
- multiple pregnancy

Question 34

Pre eclampsia mx

Answer 34

emergency secondary care assessment for any woman in whom pre-eclampsia is suspected

BP ≥ 160/110 mmHg - admitted and observed

oral labetalol is now first-line
- or Nifedipine (e.g. if asthmatic) and hydralazine

delivery of the baby is definitive management

Question 35

anaemia tx

Answer 35

oral ferrous sulfate or ferrous fumarate
- continued for 3 months after iron deficiency is corrected

cut-offs to determine whether a woman should receive oral iron therapy:
1st trimester - < 110 g/L
2nd/3rd - < 105 g/L
Postpartum - < 100 g/L

Question 36

Risk of prematurity

Answer 36

increased mortality depends on the gestation

respiratory distress syndrome

intraventricular haemorrhage

necrotizing enterocolitis

chronic lung disease, hypothermia, feeding problems, infection, jaundice

retinopathy of prematurity

hearing problems

Question 37

Preterm prelabour rupture of the membranes ix?

Answer 37

a sterile speculum examination should be performed (to look for pooling of amniotic fluid in the posterior vaginal vault)
- If not seen -> testing the fluid for placental alpha microglobulin-1 protein (PAMG-1) (e.g. AmniSure®) or insulin-like growth factor binding protein‑1

digital examination should be avoided due to the risk of infection

Question 38

Mx Preterm prelabour rupture of the membranes

Answer 38

oral erythromycin should be given for 10 days

antenatal corticosteroids should be administered to reduce the risk of respiratory distress syndrome

delivery should be considered at 34 weeks of gestation

Question 39

Reduced fetal movements mx

Answer 39

• handheld Doppler to confirm fetal heartbeat
• no HB-> immediate ultrasound
• HB -> CTG

If fetal movements have not yet been felt by 24 weeks, onward referral should be made to a maternal fetal medicine unit.

Question 40

Shoulder dystocia mx

Answer 40

Senior help should be called

McRoberts’ manoeuvre
- flexion and abduction of the maternal hips, bringing the mother’s thighs towards her abdomen
- rotation increases the relative anterior-posterior angle of the pelvis and often facilitates a successful delivery.

Question 41

Umbilical cord prolapse mx

Answer 41

• presenting part of the fetus may be pushed back into the uterus to avoid compression
• minimal handling and it should be kept warm and moist to avoid vasospasm
• patient is asked to go on ‘all fours’
• tocolytics may be used to reduce uterine contractions
• retrofilling the bladder with 500-700ml of saline