Role of Maternal Serum Alpha-Fetoprotein and Ultrasonography in Contemporary Detection of Spina Bifida

Abstract

Objective Midtrimester maternal serum alpha-fetoprotein (MSAFP) and sonographic evaluation have been used to screen for spina bifida. With the increased uptake of cell-free DNA (cfDNA) and first trimester screening, MSAFP levels may no longer be obtained routinely. Our aim was to evaluate a pediatric neurosurgical referral center database of spina bifida cases to determine the antenatal detection rate and means of diagnosis.

Study Design Nested case series of all spina bifida cases referred postnatally from 2007 to 2013. Data were abstracted from the maternal record and rates of antenatal detection with MSAFP and sonographic screening were determined.

Results Of the 105 postnatally referred cases, 11.4% (12/105) were not identified until delivery. Overall, 39% of the cases had MSAFP screening. The odds ratio for sonogram-based detection of spina bifida was 4.9 (95% confidence interval, 2–11.9). Of the neonatally detected cases, 100% had prenatal care and 91.6% (11 of the 12 cases) had documented sonography.

Conclusion We have found that 11.4% of the spina bifida cases were not detected before delivery. Nine out of the 12 cases of antenatally missed spina bifida were not screened using MSAFP. Our findings support the approach of midtrimester MSAFP screening combined with sonographic evaluation. We speculate that prenatal screening with MSAFP is underutilized.

Keywords

open neural tube defect - spina bifida - MSAFP - ultrasound - prenatal screening

Note

The authors report no conflict of interest and no financial relationship with any commercial entity.

SMFM Meeting Presentation

This work was presented at the 35th Annual Scientific Meeting of the Society of Maternal Fetal Medicine; February 2–7, 2015; San Diego, CA. Abstract 634.

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