Elevated maternal serum alpha-fetoprotein levels and maternal risk factors. Their association with pregnancy complications.

Maternal serum alpha-fetoprotein (MS-AFP) screening programs identify a population of pregnant women with elevated MS-AFP values. When the levels are unassociated with a fetal anomaly, those women have a high incidence of pregnancy complications. Such patients were compared to a population with normal MS-AFP values to determine the incidence of historical risk factors and to ascertain if their presence affected the rate of pregnancy complications. A total of 358 patients were followed prospectively, 23 with elevated MS-AFP levels and 335 with normal levels (control group). Historical risk factors were more frequent in the patients with elevated MS-AFP levels. There was a fourfold increase in the rate of pregnancy complications when a patient had both risk factors and elevated MS-AFP levels as compared with elevated MS-AFP levels alone. In the control group, patients with known risk factors experienced twice the incidence of pregnancy complications as did patients with no risk factors. Using multiple logistic regression analysis, elevated MS-AFP levels were shown to be an independent variable in the risk assessment. The results of this study have wide application in the counseling and follow-up of patients identified by MS-AFP screening programs.