Fertility and outcome of pregnancy in women exposed in utero to diethylstilbestrol.

Fertility and outcome of pregnancy were examined in women participating in the National Cooperative Diethylstilbestrol Adenosis (DESAD) Project. We compared 618 subjects who had prenatal exposure to DES with 618 control subjects. Fertility, measured in terms of pregnancies achieved, did not differ between the women exposed to DES and the controls. An increased risk of unfavorable outcome of pregnancy was associated with DES exposure (the relative risk of any unfavorable outcome of pregnancy was 1.69; P less than 0.001). Speculation on biologic mechanisms that might produce this difference is premature, since additional data about these subjects must be collected. Among DES-exposed women who became pregnant, 81 per cent had at least one full-term live birth.