We compared serum concentrations of immunoreactive inhibin, hCG, and FSH in normal women with those of two groups of women lacking endogenous luteal function. Twelve functionally agonadal, hypergonadotropic women with premature ovarian failure were given replacement ovarian steroids. Donor oocytes were fertilized in vitro with the husband's semen, and embryos were transferred into these women. A second group of 12 women were normogonadotropic but anovulatory, had undergone previously unsuccessful in vitro fertilization, and possessed cryopreserved embryos. These women were suppressed with a GnRH agonist before sex hormone replacement. Serum samples collected at weeks 2, 3, 4-6, 8-10, and 12-14 of pregnancy were measured for FSH, hCG, and immunoreactive inhibin. Data were compared with concentrations in normally ovulating women with well-established dates of conception. Sex steroid replacement hormone levels did not differ between the ovarian-failure and agonist-suppressed women and approximated that of normal cycles until pregnancy; thereafter, estradiol and progesterone levels remained higher than normal. Despite excessive steroid replacement, FSH remained higher in women with ovarian failure than in agonist-suppressed or normal women. On immunoassay, inhibin failed to show an early rise at 4-6 weeks of pregnancy in either group of aluteal women (0.52 +/- 0.05 ng/mL), whereas normal women demonstrated 0.9 +/- 0.05 ng/mL inhibin in their sera (P less than .001). By 8-10 weeks of pregnancy, women with ovarian failure demonstrated inhibin concentrations identical to those of normal women (1.2 +/- 0.1 and 1.2 +/- 0.15 ng/mL, respectively), whereas agonist-suppressed women lagged behind (0.7 +/- 0.1 ng/mL) (P less than .02).(ABSTRACT TRUNCATED AT 250 WORDS)