Outcome of pregnancy in patients with unexplained elevated or low levels of maternal serum alpha-fetoprotein.

Data relating to the outcome of pregnancy were gathered prospectively on patients with elevations of maternal serum alpha-fetoprotein (MSAFP) or with unusually low MSAFP levels (0.25 or fewer multiples of the median) unexplained by ultrasonography. Patients with unexplained MSAFP elevations (2.5 or more multiples of the median, amniotic fluid AFP normal) exhibited a significantly increased incidence of fetal loss, low birth weight, neonatal death, and fetal congenital anomalies compared with controls with normal MSAFP. Patients with unexplained low levels of MSAFP had a significantly greater risk of fetal loss than controls, but there was no increase in the incidence of low birth weight, neonatal deaths, or congenital anomalies.