Pregnancies associated with low maternal serum alpha-fetoprotein concentrations

Abstract

PIP: A program of routine screening for antenatal detection of neural tube defects by alpha fetoprotein (AFP) testing is described. It was decided to determine the outcome of all pregnancies in which the patients exhibited a low AFP level during the screening process. From May 1975 to September 1976, 3% (53 cases) of the 2100 women tested had low AFP levels. Since maternal serum AFP levels rise with increasing gestational age until 32 weeks, a large number of women with low AFP levels actually have gestational ages more advanced than originally thought. That was true in this test. Ultrasonic examination of the cases with low AFP levels halped in revision gestational ages for some of the women. Among the 49 women with low AFP levels at gestational ages from 12-16 weeks, 12% had a spontaneous abortion eventually, 2% (or 1 case) had a macerated stillborn infant, and 1 woman was not pregnant. All 4 of the women with low AFP levels at gestational ages above 16 weeks had their gestational ages revised downward following ultrasonic examination. The study show that most women with low AFP levels eventually deliver a normal infant; a low AFP level does appear to be associated with spontaneous abortion. A larger study might identify association with other abnormalities. The study data was graphed and tabulated.