We compared serum concentrations of total and free testosterone, androstenedione, dehydroepiandrosterone sulfate (DHEAS), and sex-hormone-binding globulin in 40 pregnant women exhibiting consistent alcohol abuse and in 20 abstinent pregnant controls. Sixteen drinkers gave birth to infants with fetal alcohol effects; the remaining 24 drinkers delivered healthy infants. Drinking patients with healthy infants had normal concentrations of total and free testosterone, sex-hormone-binding globulin, and DHEAS, but their levels of androstenedione increased between weeks 20-40 of pregnancy. Maternal drinking leading to fetal alcohol effects was accompanied by lowered concentrations of sex-hormone-binding globulin throughout pregnancy and by low total testosterone concentrations, although the latter difference reached statistical significance only at 16-20 weeks' gestation. In contrast, drinking leading to fetal damage was associated with higher free testosterone levels between weeks 16-20 of pregnancy and lowered concentrations of DHEAS between weeks 16-32 of gestation, whereas the androstenedione levels tended to be high throughout pregnancy. These changes in androgens can be explained in part by low sex-hormone-binding globulin concentrations, an insufficient supply of DHEAS by the adrenals, and reduced peripheral conversion of androstenedione to testosterone.