RISKS ASSOCIATED WITH AN ELEVATED MATERNAL SERUM ALPHA-FETOPROTEIN LEVEL

Among 58,187 women tested, 1002 had a maternal serum alpha-fetoprotein measuring greater-than-or-equal-to 2.5 multiples of the median after correction for race, weight, and insulin-dependent diabetes. They were stratified into three groups: group 1, 2.5 to 2.9; group 2, 3.0 to 5.0; group 3, greater-than-or-equal-to 5.0 multiples of the median. The initial risk of a serious abnormality detected at ultrasonography or amniocentesis was 17% (5%, 12%, and 65% in groups 1, 2, and 3, respectively). After correction for twins and dates, this risk became 23% (7%, 18%, and 71% In groups 1, 2, and 3, respectively). Among the women with high maternal serum alpha-fetoprotein levels, 556 (77%) had normal ultrasonographic and amniocentesis studies, and the risk of adverse pregnancy outcome was 27% (19%, 29%, and 70% in groups 1, 2, and 3, respectively). There was a statistically significant increase in late fetal and perinatal death, prematurity and growth retardation, oligohydramnios, abruptio placentae, preeclampsia, and congenital abnormalities. The overall risk for abnormality or adverse outcome was 24% in group 1, 41% in group 2, and 91% in group 3.