Limited Role of MSAFP Screening for Prenatal Omphalocele Detection

Although serum screening for aneuploidies has become less prevalent, maternal-serum alpha-fetoprotein (MSAFP) screening for body-wall defects remains widespread. We explored whether MSAFP screening is associated with earlier omphalocele detection than ultrasound alone.

This is a retrospective cohort study of prenatally detected omphalocele cases at our center from 2007 to 2023. We explored the association between MSAFP screening, gestational age at omphalocele detection, and clinical outcomes.

Among 101 pregnancies with prenatally diagnosed omphalocele, 27 (26.7%) had MSAFP screening. The median gestational age at MSAFP screening was 17 weeks 4 days. Of those who received MSAFP screening, 11 (41%) had values ≥2.5 multiples of the median (MoM) and 16 (59%) were not elevated. MSAFP results did not correlate with omphalocele size and were not associated with prenatal or postnatal outcomes. MSAFP screening did not result in earlier suspicion for or confirmation of omphalocele (P = .97 and P = .87, respectively). In contrast, first-trimester ultrasound screening was associated with earlier suspicion for and confirmation of omphalocele (P < .01 and P = .01, respectively). There were no clinical or demographic differences between those who received MSAFP screening and those who did not (including body mass index or commute distance to an urban center).

MSAFP screening is not associated with earlier omphalocele detection. Furthermore, in pregnancies with prenatally diagnosed omphalocele, the results of MSAFP screening are not predictive of clinical outcomes.