Low level of maternal serum alpha fetoprotein is associated with:

IGNOU PB Bsc Nsg.Entrance-2026

Obstetrics & Gynaecology

Easy

Appeared in: IGNOU PB Bsc Nsg.Entrance-2026

Explanation

Low maternal serum alpha-fetoprotein (MSAFP) is a key biochemical marker used in second-trimester screening for fetal aneuploidies.
A decreased MSAFP level, particularly when evaluated as part of a 'quad screen' with other markers (hCG, estriol, inhibin A), is a classic finding that increases the calculated risk for Trisomy 21 (Down's syndrome).
The underlying reason is that a fetus with Down's syndrome tends to produce less AFP, leading to lower concentrations in the maternal bloodstream.

Option A: Multiple pregnancies, such as twins or triplets, involve more than one fetus producing AFP. This leads to a higher total amount of AFP entering the maternal circulation, resulting in elevated, not low, MSAFP levels.
Option B: Fetal death often leads to the breakdown of fetal tissues, which causes AFP to leak into the amniotic fluid and subsequently into the maternal bloodstream, resulting in elevated MSAFP levels.
Option D: Anencephaly is a severe type of open neural tube defect where the fetal skull is not properly formed. This opening allows large amounts of AFP to leak directly into the amniotic fluid and maternal circulation, causing markedly elevated MSAFP levels.

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Interpretation of Maternal Serum Alpha-Fetoprotein (MSAFP) levels in prenatal screening as background academic context rather than a clinical decision trigger.
A nurse's primary role is to educate the patient that MSAFP is a screening test, not a diagnostic one. An abnormal result means further evaluation is needed, not that the baby definitely has a problem.
Counseling should include explaining that a 'positive' screen (either high or low) requires follow-up with a detailed ultrasound and offering diagnostic tests like amniocentesis for a definitive diagnosis.
Accurate gestational dating is critical. An incorrect date is a common cause of a false-positive result, as MSAFP levels change significantly each week. The nurse should confirm the dating method (e.g., last menstrual period vs. ultrasound).

How to Approach the Question

This is a factual recall question testing knowledge of prenatal screening markers.
Identify the key information in the stem: 'Low level' and 'maternal serum alpha fetoprotein (MSAFP)'.
Recall the primary associations for abnormal MSAFP levels. A useful mnemonic is 'Low is Down' (low AFP is associated with Down's syndrome).
Systematically evaluate each option against this knowledge.
Multiple pregnancy: More fetuses mean more AFP, so levels would be high. Eliminate A.
Fetal death: Tissue breakdown leads to leakage of AFP, so levels would be high. Eliminate B.

Concept Tested & Keywords

Concept Tested: Interpretation of Maternal Serum Alpha-Fetoprotein (MSAFP) levels in prenatal screening.
Stem keywords: Low level, maternal serum alpha fetoprotein, MSAFP
Lead-in keywords: associated with
Negative lead-in flag: false