Serum alpha feto-protein screening in high risk pregnancies.

We assayed alpha fetoprotein (AFP) in serum samples from 2,735 women during 14 to 20 weeks of gestation. Serum AFP levels were elevated in the presence of neural tube defect (NTD) and gut atresia in fetus, twin pregnancies, preterm delivery and neonatal complications. In two of the 23 cases of fetal NTD the diagnosis was suggested by AFP assays, with apparently normal ultrasound findings. Low maternal serum AFP levels were associated with chromosomal abnormalities and hydatidiform molar pregnancy. Calculation of risk for Down syndrome based on maternal serum AFP and maternal age helped to reduce the number of women requiring amniocentesis. Maternal serum AFP assay was helpful in the management of threatened abortion, suspected intrauterine death, and maternal toxoplasma infection. In seven cases where maternal serum AFP was high but ultrasound studies were normal, male babies were delivered. Thus maternal serum AFP assay proved useful in narrowing down the group of women requiring more detailed surveillance and diagnostic studies.