Normal pregnancy and antenatal care: cordocentesis: practice question

A OBG question in the style of the NEET PG paper. Answer it first, then read why the right option is right and why each of the others is wrong.

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OBG · Normal pregnancy and antenatal care: cordocentesis

Sample item

A fetus at 24 weeks with suspected severe anaemia needs a direct blood sample for haemoglobin and for an intrauterine transfusion. Which procedure provides access to fetal blood?

Original practice item, not a recalled exam question. Nothing here is recorded.

The answer and the reasoning

A. Cordocentesis

Percutaneous umbilical blood sampling (cordocentesis) is done under ultrasound guidance after 18 weeks, usually at the placental cord insertion. It gives fetal blood for counts, karyotype and infection tests, and allows intrauterine transfusion.

Option by option

  • A. Cordocentesis (correct)

    Correct. Cordocentesis samples fetal blood from the umbilical vein and permits transfusion.

  • B. Chorionic villus sampling

    Chorionic villus sampling collects placental tissue early in pregnancy and gives no fetal blood.

  • C. Fetoscopic skin biopsy

    Fetal skin biopsy is used for rare genodermatoses and does not give blood.

  • D. Transabdominal amniocentesis

    Amniocentesis yields amniotic fluid containing fetal cells, not blood for transfusion.

Source note: Original NextPrep sample item — pending expert review. This item is original practice material awaiting independent expert review, so confirm important facts in a standard textbook.

More OBG questions

Questions about this OBG question

What is the answer to this OBG question?

The best answer is A, Cordocentesis. Percutaneous umbilical blood sampling (cordocentesis) is done under ultrasound guidance after 18 weeks, usually at the placental cord insertion.

Why is "Chorionic villus sampling" not the answer?

Chorionic villus sampling collects placental tissue early in pregnancy and gives no fetal blood.

Why is "Fetoscopic skin biopsy" not the answer?

Fetal skin biopsy is used for rare genodermatoses and does not give blood.

Why is "Transabdominal amniocentesis" not the answer?

Amniocentesis yields amniotic fluid containing fetal cells, not blood for transfusion.

What concept does this question test?

It tests Normal pregnancy and antenatal care: cordocentesis in OBG. It gives fetal blood for counts, karyotype and infection tests, and allows intrauterine transfusion.

How hard is this question?

We tag it as an application question: it asks you to use a fact on a patient or a finding. The tag is our own editorial judgement, not an official difficulty rating, so read the reason for every option, not only the answer.

How should I study Normal pregnancy and antenatal care: cordocentesis?

Learn management algorithms as steps: PPH, eclampsia, ectopic pregnancy. Then use the flashcards and the other OBG questions on this site to test what stuck.

Is this a real NEET PG question?

No. It is an original practice item (editorial status: sample, version 1). NextPrep does not publish recalled or leaked questions, and independent faculty review of this item has not been completed yet, so confirm important facts in a standard textbook.