Maternal plasma androgens in early human pregnancy.

Mean maternal plasma levels of testosterone, androstenedione, and 5 alpha-dihydrotestosterone were established from 4 to 16 weeks gestation from twice-weekly blood samples taken from 15 pregnant women. All three hormone levels were raised when compared with the non-pregnant state. There were significant differences in mean maternal plasma testosterone levels at 4 to 5 and 7 to 8 weeks gestation, when comparing women carrying male and female fetuses. Androstenedione levels in a twin pregnancy were increased throughout and testosterone levels were more than 1 SD above the mean from week 15. Steroid levels fell late in the two women who aborted. Hormone levels in three women being given progestogens were within normal limits.