Increased maternal serum 3 alpha, 17 beta-androstanediol glucuronide concentrations during pregnancy

Maternal serum concentrations of 3 alpha, 17 beta-androstanediol glucuronide (3 alpha-diol-G), a substance that reflects peripheral androgen action and tissue 5 alpha-reductase activity, were measured in 33 normal men, 51 nonpregnant women, and 51 women with uncomplicated pregnancies. The 3 alpha-diol-G concentrations in men (median, 201 ng/ml) were significantly higher than in nonpregnant women (median, 42 ng/ml) or pregnant women (median, 124 ng/ml). The concentrations in pregnant women were significantly greater than those in nonpregnant women, and there were no significant differences between trimesters in maternal 3 alpha-diol-G concentrations. There were no fetal sex differences found in maternal serum or in third-trimester amniotic fluid. These results indicate that pregnancy is associated with increased androgen production by maternal tissues and that fetal 3 alpha-diol-G production is low.