Elevated amniotic fluid alpha fetoprotein in fetal hydrocephaly

Abstract

This report associates fetal hydrocephaly with high-for-dates alpha fetoprotein (AFP) values in amniotic fluid (AF) in 4 cases. All 4 hydrocephalic pregnancies showed abnormally high AF AFP concentrations (440 1800 7300 and 4750 vs. normal range of 15-340 ng/ml). Cerebrospinal fluid (CSF) was obtained from 3 fetuses. 2 contained a high AFP concentration (6400 and 148000 ng/ml); in both cases AF AFP was greatly elevated (7300 and 1800 ng/ml). In the 3rd case the moderately elevated AF AFP (440) was associated with a similar level (345 ng/ml) in fetal CSF. The total protein concentration was abnormally high in all CSF samples but no correlation existed between the total protein and AFP in either CSF or AF. AFP in maternal and fetal sera were within normal pregnancy range. The AFP level of newborn urine (23 ng/ml) was similar to previously measured normal infant urine values. The significance of high AFP on the prognosis of these infants cannot be indicated by these results because all infants died at or shortly after delivery. Prospective studies aimed at early antenatal detection of hydrocephaly by AF AFP are warranted.