MSAFP
Pronunciation: em-es-ay-ef-pee
Also written as: MSAFP — Maternal Serum Alpha-Fetoprotein
Maternal serum alpha-fetoprotein, a screening test measuring AFP levels in maternal blood to detect neural tube defects and chromosomal abnormalities.
Full Definition
Maternal serum alpha-fetoprotein (MSAFP) is a prenatal screening test that measures levels of alpha-fetoprotein in maternal blood, typically performed between 15-20 weeks of gestation. AFP is a protein produced by the fetal liver and yolk sac that normally crosses into maternal circulation. Elevated MSAFP levels may indicate neural tube defects, multiple pregnancy, incorrect gestational age, or other fetal abnormalities. Low levels may suggest chromosomal abnormalities such as Down syndrome. MSAFP is often part of multiple marker screening protocols including triple or quadruple screens. Results are reported as multiples of the median (MoM) and require correlation with ultrasound findings for proper interpretation.
Usage
Usage note: Distinguish from amniotic fluid AFP; maternal serum specific.
In Context
- "MSAFP levels were elevated at 3.2 MoM, prompting targeted ultrasound for neural tube defects." — Screening results
- "The low MSAFP result contributed to an increased risk calculation for trisomy 21." — Genetic counseling documentation