Labor induction in humans by the injection of 18 mg of betamethasone (Celestone) into the amniotic sac was investigated in a group of 19 pregnant women. Eight of the cases were high-risk pregnancies of 36-39 weeks' gestation, and 11 were normal pregnancies of 40-42 weeks' gestation. A group of 19 women at similar stages of pregnancy served as a control group. The criterion for the efficacy of the technique was the onset of labor or rupture of the membranes within 72 hours of the injection. Contrary to other reports, it was concluded that the technique is ineffective since no significant difference was found between the experimental and control groups.