Alpha-fetoprotein test is done in pregnancy to detect?

NORCET 3 - 2022 (Shift-2)

Obstetrics & Gynaecology

Easy

Appeared in: NORCET 3 - 2022 (Shift-2)

Explanation

The Alpha-fetoprotein (AFP) test is a key component of maternal serum screening (like the triple or quad screen) performed during the second trimester.
This test measures the level of AFP, a protein made by the developing fetus, in the mother's bloodstream.
Abnormal levels of AFP can indicate an increased risk for certain birth defects.
Specifically, low levels of maternal serum AFP (MSAFP) are associated with a higher risk of chromosomal abnormalities, which are a type of genetic disorder, such as Down syndrome (Trisomy 21) and Edwards syndrome (Trisomy 18).
Elevated AFP levels are primarily associated with open neural tube defects (like spina bifida) or abdominal wall defects.

Option A: The AFP test does not measure markers related to maternal or fetal nutritional status, such as iron, folate, or vitamin levels.
Option C: While detecting a major anomaly relates to well-being, the term 'fetal well-being' in obstetrics usually refers to acute or subacute assessments of fetal oxygenation and central nervous system status.
Option D: The Estimated Date of Delivery (EDD) is determined by the date of the last menstrual period (LMP) or, more accurately, by ultrasound measurements of the fetus in the first trimester.

Visual 1: Chart - A diagram illustrating the interpretation of maternal serum AFP levels. It should show a central 'normal' range, with arrows pointing down to 'Low AFP' (associated with Trisomy 21, Trisomy 18) and up to 'High AFP' (associated with Neural Tube Defects, Abdominal Wall Defects).

Clinical Relevance

Nursing practice connection: This is primarily an exam-oriented knowledge point with limited direct bedside application, so retain Maternal serum alpha-fetoprotein (MSAFP) screening as background academic context rather than a clinical decision trigger.
A nurse's primary role is to educate the patient that the AFP test is a screening tool, not a diagnostic test. An abnormal result indicates increased risk, not a definitive diagnosis, and requires follow-up testing like a detailed ultrasound or amniocentesis.
It is crucial to ensure the gestational age is accurate, as AFP levels change weekly. An incorrect date can lead to a false-positive result, causing unnecessary anxiety.
Nurses must provide emotional support and clear, unbiased information to parents facing an abnormal screening result, helping them navigate the options for further diagnostic testing.

How to Approach the Question

First, identify the core subject of the question, which is the purpose of the 'Alpha-fetoprotein (AFP) test' in pregnancy.
This is a factual recall question. Access your knowledge about common prenatal screening tests.
Recall what AFP is (a fetal protein) and what its measurement in maternal serum is used for.
Evaluate each option against the known purposes of the AFP test.
Remember that low AFP is linked to chromosomal abnormalities (genetic disorders) and high AFP is linked to neural tube defects.
Select the option that best encompasses these screening functions. 'Genetic disorders' is the most fitting choice as it includes conditions like Down syndrome, which is a primary target of this screening.

Concept Tested & Keywords

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