A 29-year-old Rh D-negative second gravida, whose first baby needed an exchange transfusion for haemolytic disease, has an indirect Coombs titre of 1:64 at 22 weeks. Ultrasound shows no hydrops. Which test should be used to monitor this fetus for anaemia?

Middle cerebral artery peak systolic velocity

Amniotic fluid bilirubin by ΔOD450

Umbilical artery Doppler indices

Repeat indirect Coombs titre monthly

A 27-year-old with a dichorionic twin pregnancy at 37 weeks is in early labour. Ultrasound shows the first twin in breech presentation and the second twin cephalic. She asks why the doctor advises caesarean section. Which complication of vaginal birth is the main concern?

Placental abruption from the start

Twin-twin transfusion in labour

A 27-year-old at 35 weeks with suspected FGR has the following Doppler indices: middle cerebral artery pulsatility index (PI) 1.1 and umbilical artery PI 1.4. The fetal medicine unit takes a cerebroplacental ratio (MCA PI divided by UA PI) below 1 as abnormal. How should this result be read?

Abnormal ratio showing redistribution to the brain

Abnormal ratio showing high cerebral resistance

A ratio that cannot be read without the ductus venosus

Normal ratio showing adequate placental flow

A 26-year-old Rh-negative woman received anti-D 300 µg at 28 weeks. She delivers an Rh-positive baby at 39 weeks, and her indirect Coombs test now shows anti-D at a titre of 1:2. The intern says she is now sensitised and does not need postnatal anti-D. What is the correct decision?

Give postnatal anti-D; the antibody is passive

Give anti-D only if the titre rises

Check the titre after 6 weeks, then decide

Withhold anti-D as she is sensitised

Rh isoimmunisation, multiple pregnancy and FGR

33 NEET-PG practice questions on Rh isoimmunisation, multiple pregnancy and FGR, part of Obstetrics & Gynaecology. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Medium
A 29-year-old Rh D-negative second gravida, whose first baby needed an exchange transfusion for haemolytic disease, has an indirect Coombs titre of 1:64 at 22 weeks. Ultrasound shows no hydrops. Which test should be used to monitor this fetus for anaemia?
1. AAmniotic fluid bilirubin by ΔOD450
2. BUmbilical artery Doppler indices
3. CRepeat indirect Coombs titre monthly
4. DMiddle cerebral artery peak systolic velocity
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Answer: D · Middle cerebral artery peak systolic velocity
An anaemic fetus has thinner blood and a higher cardiac output, so blood flows faster in the middle cerebral artery; a peak systolic velocity above 1.5 multiples of the median predicts moderate or severe anaemia. This non-invasive Doppler has replaced amniocentesis for ΔOD450 in monitoring. When it is raised, cordocentesis confirms the haematocrit and intrauterine transfusion can be given. After a previously affected pregnancy the titre no longer predicts severity, so serial MCA Doppler is used directly.
- A: ΔOD450 needs repeated amniocentesis and has been replaced by MCA Doppler.
- B: Umbilical artery Doppler assesses placental resistance in growth restriction.
- C: After an affected baby, titres do not reflect fetal severity.
Question 2 · Medium
A 27-year-old with a dichorionic twin pregnancy at 37 weeks is in early labour. Ultrasound shows the first twin in breech presentation and the second twin cephalic. She asks why the doctor advises caesarean section. Which complication of vaginal birth is the main concern?
1. APlacental abruption from the start
2. BLocking of the twins' chins
3. CCord entanglement of the twins
4. DTwin-twin transfusion in labour
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Answer: B · Locking of the twins' chins
When the first twin is breech and the second cephalic, the after-coming head of the first can lock with the head of the second, chin to chin, during vaginal birth. Locked twins are rare but often fatal for the first twin, and a breech first twin is a common reason for caesarean in twins. When the first twin is cephalic, vaginal birth is usually possible whatever the second twin's presentation. Cord entanglement and twin-twin transfusion are complications of monochorionic placentation.
- A: Abruption can follow delivery of the first twin but is not the main concern here.
- C: Cord entanglement is a risk of monoamniotic, not dichorionic, twins.
- D: TTTS occurs only in monochorionic twins.
Question 3 · Easy
A 29-year-old at 32 weeks with chronic hypertension is clinically small for dates. Ultrasound biometry is ordered to look for fetal growth restriction. Which single measurement is the most sensitive for detecting growth restriction?
1. AHead circumference
2. BBiparietal diameter
3. CAbdominal circumference
4. DFemur length
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Answer: C · Abdominal circumference
Abdominal circumference reflects liver size, which falls early in placental insufficiency because glycogen stores are used up, so it is the most sensitive single measurement for growth restriction. An AC or estimated fetal weight below the 10th centile prompts Doppler study. The head is spared until late in asymmetric growth restriction, so head measurements stay normal for longer. Femur length is used to date pregnancy and is less sensitive to placental insufficiency.
- A: Head circumference is preserved by brain sparing.
- B: BPD is spared until late in asymmetric growth restriction.
- D: Femur length is less affected by early placental insufficiency.
Question 4 · Medium
A 27-year-old at 35 weeks with suspected FGR has the following Doppler indices: middle cerebral artery pulsatility index (PI) 1.1 and umbilical artery PI 1.4. The fetal medicine unit takes a cerebroplacental ratio (MCA PI divided by UA PI) below 1 as abnormal. How should this result be read?
1. AAbnormal ratio showing high cerebral resistance
2. BAbnormal ratio showing redistribution to the brain
3. CA ratio that cannot be read without the ductus venosus
4. DNormal ratio showing adequate placental flow
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Answer: B · Abnormal ratio showing redistribution to the brain
The cerebroplacental ratio is 1.1/1.4 = 0.79, below 1, so it is abnormal. It falls when placental resistance rises (higher UA PI) and the fetus dilates its cerebral vessels to protect the brain (lower MCA PI), the 'brain-sparing' response to hypoxaemia. A low ratio predicts fetal compromise and adverse outcome, particularly in late-onset FGR, where umbilical artery Doppler alone may still look normal. It prompts closer surveillance and planned delivery.
- A: A low ratio means low, not high, cerebral resistance.
- C: The ratio is read on its own; ductus venosus is used in early-onset FGR.
- D: The ratio of 0.79 is below the cut-off of 1.
Question 5 · Hard
A 26-year-old Rh-negative woman received anti-D 300 µg at 28 weeks. She delivers an Rh-positive baby at 39 weeks, and her indirect Coombs test now shows anti-D at a titre of 1:2. The intern says she is now sensitised and does not need postnatal anti-D. What is the correct decision?
1. AGive anti-D only if the titre rises
2. BCheck the titre after 6 weeks, then decide
3. CWithhold anti-D as she is sensitised
4. DGive postnatal anti-D; the antibody is passive
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Answer: D · Give postnatal anti-D; the antibody is passive
Anti-D given at 28 weeks is still detectable at delivery in many women, usually at a low titre such as 1:2 to 1:4. This passive antibody does not mean active immunisation, and the standard postnatal dose must still be given within 72 hours after an Rh-positive birth. Withholding it because of a passive antibody is a common error that leaves the woman unprotected. A higher titre or a history without antenatal prophylaxis would suggest true sensitisation.
- A: Waiting for a rise misses the 72-hour window.
- B: Delaying 6 weeks is far beyond the protective window.
- C: A low titre after antenatal anti-D is passive, not true sensitisation.
Question 6 · Medium
A 30-year-old with pre-eclampsia at 34 weeks has a fetus with estimated weight below the 3rd centile. Umbilical artery Doppler now shows absent end-diastolic flow; the ductus venosus is normal and the CTG is reactive. What is the most appropriate management?
1. AAwait spontaneous labour at term
2. BStart low-dose aspirin and continue
3. CPlan delivery now
4. DRepeat Doppler after one week
Answer and explanation in LearnFree account
Question 7 · Easy
An early scan of a 27-year-old with a spontaneous monozygotic twin pregnancy shows features that fit division of the embryo on day 6 after fertilisation. What type of twin pregnancy is expected?
1. AMonochorionic monoamniotic
2. BConjoined twins
3. CMonochorionic diamniotic
4. DDichorionic diamniotic
Answer and explanation in LearnFree account
Question 8 · Easy
A baby born to an Rh-isoimmunised mother has a cord haemoglobin of 11 g/dL and a rapidly rising serum bilirubin despite intensive phototherapy, and the neonatologist plans an exchange transfusion. Which blood should be used?
1. ABaby's own group, Rh-positive, crossmatched with baby
2. BO Rh-negative, crossmatched with the mother's serum
3. CAB Rh-negative, crossmatched with the father's cells
4. DO Rh-positive, crossmatched with the mother's serum
Answer and explanation in LearnFree account
Question 9 · Medium
A 30-year-old at 24 weeks has a twin pregnancy in which the sonologist sees no dividing membrane between the twins despite a careful search, with a single placenta. Both twins are growing normally. What is the most important specific risk in this pregnancy?
1. ARh isoimmunisation from fetal bleeding
2. BLocking of the twins in the first trimester
3. CCord entanglement causing sudden fetal death
4. DTwin reversed arterial perfusion later on
Answer and explanation in LearnFree account
Question 10 · Medium
A baby weighing 1.9 kg is born at 38 weeks to a mother with chronic hypertension. At 3 hours of age the baby is jittery and the blood glucose is 32 mg/dL. The paediatrician explains why growth-restricted babies are prone to this. What is the main reason?
1. AIncreased glucose loss in the urine
2. BExcess insulin from fetal islet hyperplasia
3. CAbsent cortisol response to stress
4. DReduced hepatic glycogen and fat stores
Answer and explanation in LearnFree account
Question 11 · Hard
A 28-year-old Rh-negative woman whose first baby had severe haemolytic disease is now 11 weeks pregnant. Her husband is Rh D positive and his genotype is heterozygous (Dd). She is anxious about months of Doppler scans. Which test can best show, without risk to the pregnancy, whether this fetus is at risk?
1. ACell-free fetal DNA for RHD genotype
2. BKleihauer-Betke test on maternal blood
3. CChorionic villus sampling for fetal blood group
4. DIndirect Coombs titre repeated every month
Answer and explanation in LearnFree account
Question 12 · Medium
A 30-year-old Rh-negative second gravida did not receive anti-D after her first delivery at home. At 16 weeks now, her indirect Coombs test is positive with an anti-D titre of 1:8. She asks whether an anti-D injection now will protect this baby. What is the correct advice?
1. AAnti-D is useless now; monitor the fetus
2. BAnti-D should be given monthly till delivery
3. CA double dose of anti-D will prevent fetal anaemia
4. DAnti-D 300 µg now will reverse the sensitisation
Answer and explanation in LearnFree account
Question 13 · Easy
A 25-year-old Rh D-negative primigravida, whose indirect Coombs test was negative throughout pregnancy, delivers a healthy baby whose cord blood is Rh D positive. What is the standard dose and timing of anti-D immunoglobulin for her in Indian practice?
1. A100 µg IV within 7 days of delivery
2. B300 µg IM within 72 hours of delivery
3. C300 µg IM at the postnatal visit at 6 weeks
4. D50 µg IM within 72 hours of delivery
Answer and explanation in LearnFree account
Question 14 · Easy
A 31-year-old Rh-negative woman has an abruption with a large fetomaternal haemorrhage suspected at 34 weeks. The obstetrician wants to know how many doses of anti-D she needs. Which test measures the volume of fetal blood in her circulation?
1. AKleihauer-Betke acid elution test
2. BDirect Coombs test on maternal blood
3. CApt test on vaginal blood
4. DIndirect Coombs titre on maternal serum
Answer and explanation in LearnFree account
Question 15 · Medium
During the first-trimester scan of a 28-year-old with twins at 12 weeks, the sonologist records four findings: 1. A thick dividing membrane with a triangular projection of placental tissue at its base. 2. Twins of different sexes. 3. Two separate placentas. 4. A thin dividing membrane meeting the placenta at a right angle. Which findings indicate a dichorionic pregnancy?
1. A1, 2 and 3 only
2. B1, 2, 3 and 4
3. C1 and 3 only
4. D2, 3 and 4 only
Answer and explanation in LearnFree account
Question 16 · Medium
In an unsensitised Rh D-negative pregnant woman, the registrar reviews events after which anti-D immunoglobulin should be given within 72 hours: 1. Amniocentesis at 16 weeks. 2. External cephalic version at 37 weeks. 3. A woman with an anti-D titre of 1:32 who has a minor fall. 4. Abdominal trauma in a road accident at 30 weeks. Which events need anti-D?
1. A1 and 2 only
2. B1, 2, 3 and 4
3. C1, 2 and 4 only
4. D2, 3 and 4 only
Answer and explanation in LearnFree account
Question 17 · Medium
At an ANC clinic, the registrar sorts causes of fetal growth restriction into the symmetric (early, global) and asymmetric (late, head-sparing) types: 1. Congenital cytomegalovirus infection. 2. Trisomy 18. 3. Pre-eclampsia from 30 weeks. 4. Fetal alcohol exposure throughout pregnancy. Which causes typically produce symmetric FGR?
1. A2, 3 and 4 only
2. B1 and 2 only
3. C1, 2, 3 and 4
4. D1, 2 and 4 only
Answer and explanation in LearnFree account
Question 18 · Medium
A term baby girl weighs 2,000 g and is 48 cm long. The neonatologist calculates the ponderal index as birth weight in grams x 100 divided by length in cm cubed, and the unit takes a value below 2.0 as typical of asymmetric growth restriction. What is her ponderal index and what does it suggest?
1. AAbout 0.9; severe symmetric restriction
2. BAbout 4.2; normal fetal growth
3. CAbout 2.4; symmetric growth restriction
4. DAbout 1.8; asymmetric growth restriction
Answer and explanation in LearnFree account
Question 19 · Medium
A 31-year-old at 30 weeks with a twin pregnancy has estimated fetal weights of 1,600 g and 1,200 g on ultrasound. The unit calculates discordance as (larger EFW - smaller EFW) divided by the larger EFW, and takes 20% or more as significant. What is the discordance and is it significant?
1. A14%; not significant
2. B25%; significant
3. C40%; significant
4. D33%; significant
Answer and explanation in LearnFree account
Question 20 · Hard
A 28-year-old with severe early-onset FGR at 30 weeks (estimated weight below the 3rd centile) has umbilical artery Doppler showing reversed end-diastolic flow. The ductus venosus a-wave is still positive, and the computerised CTG shows reduced short-term variation. What is the most appropriate plan?
1. ARepeat Dopplers twice weekly until 34 weeks
2. BInduce labour with prostaglandin gel today
3. CSteroids, magnesium, then caesarean
4. DBed rest with high-protein diet and review
Answer and explanation in LearnFree account
Question 21 · Medium
A 25-year-old with a dichorionic twin pregnancy at 22 weeks asks at the ANC clinic which complication is most likely to affect her twins. The counselling doctor wants to name the commonest serious complication of twin pregnancy. Which is it?
1. ATwin-twin transfusion syndrome
2. BCongenital malformations
3. CPost-term pregnancy
4. DPreterm birth
Answer and explanation in LearnFree account
Question 22 · Hard
A 33-year-old with a monochorionic diamniotic twin pregnancy is found at 28 weeks to have one twin dead in utero; the other twin is moving and has a normal CTG and normal MCA Doppler. She is stable with normal coagulation. What is the most appropriate management?
1. AImmediate caesarean delivery of the live twin
2. BInduce labour today to deliver both twins
3. CContinue the pregnancy with close surveillance
4. DStart heparin to prevent maternal DIC
Answer and explanation in LearnFree account
Question 23 · Medium
A 28-year-old Rh-isoimmunised woman at 27 weeks has a fetus with ascites, scalp oedema and a pericardial effusion on ultrasound. A student asks how severe fetal anaemia leads to hydrops. Which mechanism is the main one?
1. APolyhydramnios compresses the fetal venous return
2. BLiver erythropoiesis lowers albumin, raises portal pressure
3. CFetal hyperbilirubinaemia causes renal failure and fluid retention
4. DMaternal antibodies damage fetal capillaries directly
Answer and explanation in LearnFree account
Question 24 · Medium
In the labour room of a medical college, a 25-year-old delivers the first of dichorionic twins vaginally at 38 weeks. On abdominal palpation the second twin lies transverse with its back up; membranes are intact and the fetal heart is 140/min. The obstetrician is experienced. What is the most appropriate next step for the second twin?
1. AInternal podalic version and breech extraction
2. BOxytocin infusion to encourage descent
3. CWait for spontaneous correction for two hours
4. DImmediate caesarean section for the second twin
Answer and explanation in LearnFree account
Question 25 · Medium
A 24-year-old Rh D-negative primigravida whose husband is Rh D positive attends the ANC clinic at 28 weeks. Her indirect Coombs test is negative and the pregnancy is uneventful. What is the most appropriate step now?
1. AGive anti-D 300 µg IM now
2. BRepeat indirect Coombs at 32 weeks only
3. CGive anti-D only after delivery
4. DCheck middle cerebral artery Doppler
Answer and explanation in LearnFree account

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Rh isoimmunisation, multiple pregnancy and FGR

A 29-year-old Rh D-negative second gravida, whose first baby needed an exchange transfusion for haemolytic disease, has an indirect Coombs titre of 1:64 at 22 weeks. Ultrasound shows no hydrops. Which test should be used to monitor this fetus for anaemia?

A 27-year-old with a dichorionic twin pregnancy at 37 weeks is in early labour. Ultrasound shows the first twin in breech presentation and the second twin cephalic. She asks why the doctor advises caesarean section. Which complication of vaginal birth is the main concern?

A 29-year-old at 32 weeks with chronic hypertension is clinically small for dates. Ultrasound biometry is ordered to look for fetal growth restriction. Which single measurement is the most sensitive for detecting growth restriction?

A 27-year-old at 35 weeks with suspected FGR has the following Doppler indices: middle cerebral artery pulsatility index (PI) 1.1 and umbilical artery PI 1.4. The fetal medicine unit takes a cerebroplacental ratio (MCA PI divided by UA PI) below 1 as abnormal. How should this result be read?

A 26-year-old Rh-negative woman received anti-D 300 µg at 28 weeks. She delivers an Rh-positive baby at 39 weeks, and her indirect Coombs test now shows anti-D at a titre of 1:2. The intern says she is now sensitised and does not need postnatal anti-D. What is the correct decision?

A 30-year-old with pre-eclampsia at 34 weeks has a fetus with estimated weight below the 3rd centile. Umbilical artery Doppler now shows absent end-diastolic flow; the ductus venosus is normal and the CTG is reactive. What is the most appropriate management?

An early scan of a 27-year-old with a spontaneous monozygotic twin pregnancy shows features that fit division of the embryo on day 6 after fertilisation. What type of twin pregnancy is expected?

A baby born to an Rh-isoimmunised mother has a cord haemoglobin of 11 g/dL and a rapidly rising serum bilirubin despite intensive phototherapy, and the neonatologist plans an exchange transfusion. Which blood should be used?

A 30-year-old at 24 weeks has a twin pregnancy in which the sonologist sees no dividing membrane between the twins despite a careful search, with a single placenta. Both twins are growing normally. What is the most important specific risk in this pregnancy?

A baby weighing 1.9 kg is born at 38 weeks to a mother with chronic hypertension. At 3 hours of age the baby is jittery and the blood glucose is 32 mg/dL. The paediatrician explains why growth-restricted babies are prone to this. What is the main reason?

A 30-year-old Rh-negative second gravida did not receive anti-D after her first delivery at home. At 16 weeks now, her indirect Coombs test is positive with an anti-D titre of 1:8. She asks whether an anti-D injection now will protect this baby. What is the correct advice?

A 25-year-old Rh D-negative primigravida, whose indirect Coombs test was negative throughout pregnancy, delivers a healthy baby whose cord blood is Rh D positive. What is the standard dose and timing of anti-D immunoglobulin for her in Indian practice?

A 31-year-old Rh-negative woman has an abruption with a large fetomaternal haemorrhage suspected at 34 weeks. The obstetrician wants to know how many doses of anti-D she needs. Which test measures the volume of fetal blood in her circulation?

A term baby girl weighs 2,000 g and is 48 cm long. The neonatologist calculates the ponderal index as birth weight in grams x 100 divided by length in cm cubed, and the unit takes a value below 2.0 as typical of asymmetric growth restriction. What is her ponderal index and what does it suggest?

A 31-year-old at 30 weeks with a twin pregnancy has estimated fetal weights of 1,600 g and 1,200 g on ultrasound. The unit calculates discordance as (larger EFW - smaller EFW) divided by the larger EFW, and takes 20% or more as significant. What is the discordance and is it significant?

A 25-year-old with a dichorionic twin pregnancy at 22 weeks asks at the ANC clinic which complication is most likely to affect her twins. The counselling doctor wants to name the commonest serious complication of twin pregnancy. Which is it?

A 33-year-old with a monochorionic diamniotic twin pregnancy is found at 28 weeks to have one twin dead in utero; the other twin is moving and has a normal CTG and normal MCA Doppler. She is stable with normal coagulation. What is the most appropriate management?

A 28-year-old Rh-isoimmunised woman at 27 weeks has a fetus with ascites, scalp oedema and a pericardial effusion on ultrasound. A student asks how severe fetal anaemia leads to hydrops. Which mechanism is the main one?

A 24-year-old Rh D-negative primigravida whose husband is Rh D positive attends the ANC clinic at 28 weeks. Her indirect Coombs test is negative and the pregnancy is uneventful. What is the most appropriate step now?