In which condition maternal serum alpha feto protein (MSAFP) level increased?

NORCET-7 Mains-2024

Obstetrics & Gynaecology

Easy

Appeared in: NORCET-7 Mains-2024

Explanation

Maternal serum alpha-fetoprotein (MSAFP) is a protein produced primarily by the developing fetus.
Its level is measured in the mother's blood as a key part of second-trimester prenatal screening.
In a multiple pregnancy (e.g., twins, triplets), each fetus produces AFP, leading to a cumulative higher level in the maternal bloodstream compared to a pregnancy with a single fetus.
Therefore, multiple gestation is a well-established cause of an elevated MSAFP reading.

Option A: Down syndrome (Trisomy 21) is characteristically associated with a decreased MSAFP level.
Option B: Pre-existing maternal diabetes is generally associated with lower MSAFP levels.
Option D: Maternal obesity is associated with decreased MSAFP levels.

Visual 1: Chart: A two-column chart listing conditions that cause elevated MSAFP (e.g., multiple gestation, neural tube defects, abdominal wall defects) and conditions that cause decreased MSAFP (e.g., Down syndrome, Trisomy 18, maternal diabetes, obesity).

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.
MSAFP is a screening tool, not a diagnostic test. A nurse must counsel patients that an abnormal result indicates a higher risk, not a definite problem, and that further diagnostic testing (like ultrasound or amniocentesis) is required.
Accurate gestational dating is the most critical factor for interpreting MSAFP results. An incorrect date is the most common non-pathological reason for an abnormal result, causing significant patient anxiety.
What if? If the gestational age was underestimated by two weeks, the MSAFP value would be compared against the median for an earlier gestational week. Since MSAFP levels rise with gestation, this would make the result appear falsely elevated, potentially leading to unnecessary anxiety and invasive follow-up tests.

How to Approach the Question

This is a factual recall question testing knowledge of prenatal screening markers.
First, identify the key components of the question: 'Maternal Serum Alpha Feto Protein (MSAFP)' and the keyword 'increased'.
Systematically evaluate each option based on your knowledge of how it affects MSAFP levels.
Option A, Down syndrome: Recall that this chromosomal abnormality is associated with low MSAFP.
Option B, Diabetes: Recall that maternal diabetes is associated with low MSAFP.
Option C, Multiple pregnancy: Reason logically that two or more fetuses will produce more AFP than one, leading to an increased level in the mother's blood.

Concept Tested & Keywords

Concept Tested: Interpretation of Maternal Serum Alpha-Fetoprotein (MSAFP) levels in prenatal screening.
Stem keywords: maternal serum alpha feto protein, MSAFP, increased
Lead-in keywords: In which condition
Negative lead-in flag: false

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