Fetal medicine and prenatal diagnosis

52 NEET-PG practice questions on Fetal medicine and prenatal diagnosis, 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.

1. Question 1 · Medium

   The Central Supervisory Board under the PCPNDT Act reviews how the Act works, advises the government on policy and lays down a code of conduct. Who chairs it?

   1. AThe President of the National Medical Commission
   2. BThe Chief Justice of the High Court
   3. CThe Union Minister of Health and Family Welfare
   4. DThe Director General of Health Services

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   Answer: C · The Union Minister of Health and Family Welfare

   Section 7 sets up the Central Supervisory Board, chaired by the Union Minister in charge of Health and Family Welfare. It reviews the working of the Act, advises on policy and lays down a code of conduct.

   • A: The NMC regulates medical education, not this board.
   • B: The judiciary has no seat as chair of the board.
   • D: The DGHS is a member, not the chair.

   Remember this

   The PCPNDT Central Supervisory Board is chaired by the Union Health Minister.

2. Question 2 · Medium

   After amniocentesis at 16 weeks for a high-risk screen with a normal scan, the couple ask for the fastest result for the common trisomies. Which test gives it within about 1-2 days?

   1. AFull karyotype after culture
   2. BWhole-exome sequencing
   3. CQF-PCR
   4. DMaternal serum free beta-hCG

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   Answer: C · QF-PCR

   Quantitative fluorescent PCR counts polymorphic markers on chromosomes 13, 18, 21, X and Y in uncultured cells and gives a result within 24-48 hours. A full karyotype needs cell culture and takes about 2 weeks.

   • A: Karyotyping needs about 2 weeks of culture.
   • B: Exome sequencing takes weeks and is for anomalies with a normal microarray.
   • D: Maternal serum markers are screening tests, not a diagnosis.

   Remember this

   QF-PCR gives a rapid result for common aneuploidies within 1-2 days of the sample.

3. Question 3 · Medium

   During counselling at 15 weeks, a woman asks how much amniocentesis adds to her risk of miscarriage. According to the RCOG guideline of 2021, what should she be told?

   1. AAbout 2%
   2. BProbably below 0.5%
   3. CAbout 5%
   4. DNo added risk at all

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   Answer: B · Probably below 0.5%

   Recent large studies and the RCOG 2021 guideline put the additional miscarriage risk from amniocentesis, and from CVS, at probably below 0.5%, lower than older figures of 1%. Risk is lower in experienced hands.

   • A: 2% is the order of loss after cordocentesis, not amniocentesis.
   • C: 5% is far higher than any modern estimate.
   • D: There is a small added risk, so 'none' is wrong.

   Remember this

   The added miscarriage risk from amniocentesis or CVS is probably below 0.5%.

4. Question 4 · Easy

   Under the PCPNDT Act, the record of every ultrasound done on a pregnant woman is kept in which form?

   1. AForm F
   2. BForm G
   3. CForm H
   4. DForm A

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   Answer: A · Form F

   Every genetic clinic, ultrasound clinic or imaging centre must fill Form F for each pregnant woman scanned, with the referral, indication and findings, and keep it for inspection. Gaps in Form F are treated as breaches of the Act.

   • B: Form G is the consent form for invasive procedures.
   • C: Form H is the register kept by the Appropriate Authority.
   • D: Form A is the application for registration.

   Remember this

   Form F is the mandatory record of every prenatal ultrasound under the PCPNDT Act.

5. Question 5 · Medium

   Under the PCPNDT Act, an invasive prenatal diagnostic procedure may be done only if the woman meets set criteria. Consider these: 1. age above 35 years; 2. two or more spontaneous abortions or fetal losses; 3. exposure to potentially teratogenic drugs, radiation or infection; 4. a wish to know the fetal sex after two daughters. Which are valid criteria?

   1. A1, 2 and 3 only
   2. B1 and 3 only
   3. C1 and 2 only
   4. D2, 3 and 4 only

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   Answer: A · 1, 2 and 3 only

   Section 4(3) allows prenatal diagnostic procedures only when the woman is above 35, has had two or more spontaneous abortions or fetal losses, was exposed to potential teratogens, or has a family history of mental retardation, physical deformity or genetic disease, or another condition named by the Board. Wanting to know the sex is never a ground.

   • B: Statement 2 is also valid.
   • C: Statement 3 is also a valid criterion.
   • D: Statement 4 is never a valid ground.

   Remember this

   PCPNDT criteria are age over 35, repeated losses, teratogen exposure and genetic family history.

6. Question 6 · Easy

   Chorionic villus sampling obtains tissue from which part of the placenta?

   1. AChorion frondosum
   2. BDecidua basalis
   3. CChorion laeve
   4. DAmnion

   Answer and explanation in LearnFree account

7. Question 7 · Medium

   During amniocentesis of a dichorionic twin pregnancy, a dye is injected into the first sac to make sure the second needle enters the other sac. Which dye must NOT be used?

   1. ASterile saline
   2. BMethylene blue
   3. CNo dye, using ultrasound mapping
   4. DIndigo carmine

   Answer and explanation in LearnFree account

8. Question 8 · Hard

   CVS done at 12 weeks for a high-risk combined test result shows trisomy 18 in some cells and a normal karyotype in others. The anomaly scan is normal. What is the next step?

   1. AReassure, as mosaicism has no meaning
   2. BAmniocentesis for fetal karyotype
   3. CTermination of pregnancy for trisomy 18
   4. DRepeat CVS in 2 weeks

   Answer and explanation in LearnFree account

9. Question 9 · Medium

   A woman whose in-laws forced her to undergo a sex-determination scan is named in a complaint under the PCPNDT Act. Unless the contrary is proved, what does the court presume?

   1. AThat her husband or relatives compelled her
   2. BThat she acted willingly with the doctor
   3. CThat the scan was for a medical reason
   4. DThat the sonologist acted alone

   Answer and explanation in LearnFree account

10. Question 10 · Hard

    Consider these statements on Doppler changes in fetal growth restriction. 1. In early-onset FGR the umbilical artery PI is usually the first vessel to become abnormal. 2. A reversed a-wave in the ductus venosus is a late sign. 3. In late-onset FGR the umbilical artery Doppler is often normal. 4. Brain-sparing is shown by a rise in middle cerebral artery PI. Which are correct?

    1. A1, 3 and 4 only
    2. B2, 3 and 4 only
    3. C1 and 2 only
    4. D1, 2 and 3 only

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11. Question 11 · Medium

    A city sonologist posts on social media that his clinic offers '100% accurate boy or girl scans'. Under which provision is this an offence?

    1. ABan on advertising sex determination
    2. BBan on scans before 12 weeks
    3. CBan on teleradiology reporting
    4. DBan on private ultrasound clinics

    Answer and explanation in LearnFree account

12. Question 12 · Hard

    During an inspection by the District Appropriate Authority, a sonologist in a busy private centre is found to have Form F records missing for eleven of the obstetric scans done in the past month. He says the scans were routine growth and anomaly scans, that no fetal sex was ever disclosed, and that the gaps were only clerical errors by a new receptionist. The machine logs match the appointment book, and there is no complaint from any patient. Under the 2003 amendment to the Act, how is this record deficiency treated in law?

    1. AAs an offence only if a patient complains
    2. BAs a clerical lapse with no legal effect
    3. CAs a matter only for the State Medical Council
    4. DAs a breach unless he proves otherwise

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13. Question 13 · Medium

    At her booking visit at 10 weeks in a district hospital, a primigravida asks when the detailed fetal anomaly scan will be done and why it is not done earlier. What is the usual timing?

    1. A32-34 weeks
    2. B18-20 weeks
    3. C11-13 weeks
    4. D24-28 weeks

    Answer and explanation in LearnFree account

14. Question 14 · Easy

    Which fetal vessel's Doppler waveform best reflects cardiac function and central venous pressure in a growth-restricted fetus?

    1. AUterine artery
    2. BMiddle cerebral artery
    3. CDuctus venosus
    4. DUmbilical artery

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15. Question 15 · Medium

    Nuchal translucency of 3.8 mm is measured at 12+3 weeks, and the combined screen puts the chance of Down syndrome at 1 in 40. The woman, a bank officer, wants a definite answer as early as possible. What should she be offered?

    1. ACell-free DNA as a final diagnosis
    2. BAmniocentesis now
    3. CRepeat combined test in 2 weeks
    4. DCVS now

    Answer and explanation in LearnFree account

16. Question 16 · Medium

    Maternal serum AFP is 3.2 MoM at 16 weeks, but the ultrasound view of the spine is poor due to maternal obesity. If amniocentesis is done, which amniotic fluid finding confirms an open neural tube defect?

    1. ARaised acetylcholinesterase
    2. BLow lecithin-sphingomyelin ratio
    3. CRaised bilirubin on spectrophotometry
    4. DRaised 17-hydroxyprogesterone

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17. Question 17 · Medium

    In a primigravida who had a febrile illness with a rash at 14 weeks, the anomaly scan at 23 weeks shows symmetrical growth restriction, echogenic bowel, periventricular calcification and mild ventriculomegaly. Maternal CMV IgG has turned from negative at booking to positive, with low avidity. Which test best confirms fetal infection?

    1. ARepeat maternal IgM after 2 weeks
    2. BCVS for viral culture
    3. CAmniocentesis for CMV PCR
    4. DCordocentesis for fetal CMV IgM

    Answer and explanation in LearnFree account

18. Question 18 · Hard

    At 28 weeks, a woman from a tribal block in Wayanad is referred with severe fetal growth restriction. Her estimated fetal weight is 720 g, below the 1st centile. The umbilical artery shows reversed end-diastolic flow, and the ductus venosus a-wave is reversed on two separate scans this morning. The computerised CTG shows reduced variation. Her blood pressure is 150/100 mm Hg on nifedipine, and her renal and liver tests are normal. The parents understand the outlook, including the risk of disability, and want everything done for the baby. What is the next step?

    1. AAdmit for bed rest and maternal oxygen therapy
    2. BInduction of labour with prostaglandin gel
    3. CSteroids and magnesium sulphate, then caesarean delivery
    4. DRepeat ductus venosus Doppler in 48 hours

    Answer and explanation in LearnFree account

19. Question 19 · Medium

    On a growth scan at 33 weeks in a woman with chronic hypertension, the abdominal circumference is below the 3rd centile. The sonologist reports 'brain-sparing'. Which middle cerebral artery Doppler change is she describing?

    1. AAn early diastolic notch
    2. BReversed diastolic flow
    3. CA fall in the pulsatility index
    4. DA rise in the pulsatility index

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20. Question 20 · Medium

    Doppler at 35 weeks, estimated fetal weight on the 4th centile: umbilical artery PI 1.60 (95th centile for gestation 1.25); middle cerebral artery PI 1.10 (5th centile 1.40). How is the cerebroplacental ratio best interpreted?

    1. AAbnormal, showing cerebral redistribution
    2. BAbnormal, showing fetal anaemia
    3. CNormal, as the MCA PI alone decides
    4. DNot valid before 37 weeks

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21. Question 21 · Hard

    At the fetal medicine clinic, a woman at 16 weeks with a high-risk quadruple test result asks for amniocentesis. She was found to be HIV-positive at booking two weeks ago and has not yet started antiretroviral therapy; her viral load is 48,000 copies/mL. Her ultrasound shows an anterior placenta and no structural anomaly. She understands that the procedure carries a small risk of transmitting the virus to the baby, and she is keen to have the test today if possible, as she lives far away. What is the best plan?

    1. ADo the amniocentesis today through the placenta
    2. BRefuse invasive testing for the rest of the pregnancy
    3. COffer CVS instead, as it avoids the amniotic sac
    4. DStart ART now and sample once viral load is undetectable

    Answer and explanation in LearnFree account

22. Question 22 · Medium

    Nuchal translucency of 4.2 mm was found at 12 weeks in a second pregnancy; CVS karyotype and microarray are normal. Parents wish to continue. What further test is most important?

    1. AFetal echocardiography
    2. BRepeat CVS at 16 weeks
    3. CMaternal TORCH screen
    4. DThird-trimester MRI brain

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23. Question 23 · Medium

    A newly registered ultrasound centre in Kozhikode is preparing for inspection. Under the PCPNDT Rules, which notice must be displayed prominently?

    1. AThe names of referring doctors
    2. BThat disclosure of fetal sex is prohibited by law
    3. CThe number of scans done each month
    4. DThe fees for each type of scan

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24. Question 24 · Easy

    Small for gestational age on ultrasound is defined as an estimated fetal weight below which centile?

    1. A10th centile
    2. B3rd centile
    3. C5th centile
    4. D25th centile

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25. Question 25 · Easy

    In asymmetric fetal growth restriction due to placental insufficiency, which ultrasound ratio rises above normal?

    1. AAbdominal circumference to head circumference
    2. BAbdominal circumference to femur length
    3. CBiparietal to occipitofrontal diameter
    4. DHead circumference to abdominal circumference

    Answer and explanation in LearnFree account