Pregnancy outcome was followed in 123 women showing maternal serum alpha-fetoprotein, less than or equal to 0.50 MOM. In 28 cases AFP was secondarily considered as normal either after ultrasonography and correction of gestation age or after a second sample normal result. In 95 cases AFP level was confirmed lowered; perinatal outcome was normal in 70 cases and abnormal in 25. Among these 25 cases, 3 autosomal trisomies occurred, 2 trisomies 18 and 1 trisomy 21; in the 22 other cases, we observed antepartum risk factors (10 cases with impending premature labor or premature labor, 9 cases with chronic hypertension, 2 cases with Ag HBs hepatitis and 1 case with diabetes).