Amniotic Fluid Concentrations of Glial Fibrillary Acidic Protein Do Not Correlate with Prenatal Metrics in Fetuses with Myelomeningocele.

INTRODUCTION: We investigated the correlation of amniotic fluid (AF) concentrations of glial fibrillary acidic protein (GFAP) with prenatal features of myelomeningocele (MMC) and neurodevelopmental outcome after fetal MMC (fMMC) surgery.

MATERIALS AND METHODS: AF was collected during fMMC surgery between December 2012 and November 2015. AF-GFAP concentration was determined by ELISA. Retrospective chart review identified the characteristics of the defect. Data regarding delivery and 1-year neurodevelopmental outcome was collected from The Children's Hospital of Philadelphia fMMC Registry.

RESULTS: Eighty-two AF samples were collected from fMMC surgeries. Perinatal data were obtained from 77 subjects, and 1-year follow-up data from 65 subjects. GFAP concentrations were significantly elevated in MMC compared to myeloschisis (24.1 ± 2.9 and 10.3 ± 1.5 ng/mL; p < 0.0001). A larger percentage of subjects with myeloschisis defects delivered before their scheduled due date (myeloschisis 88.5%; MMC 55.0%; p = 0.003) and delivered at an earlier mean gestational age (34.6 ± 0.4 weeks, n = 26) compared to those with MMC defects (35.2 ± 0.4 weeks, n = 51) (p = 0.04).

DISCUSSION: AF-GFAP levels differentiate between MMC and myeloschisis, and raise interesting questions regarding the clinical significance between the 2 types of defects.