Serum inhibin as an index of ovarian function in women undergoing pituitary suppression and ovarian stimulation in an in vitro fertilization program.

Serum inhibin concentrations, determined by radioimmunoassay, were measured in women undergoing pituitary suppression with buserelin and subsequently ovarian stimulation with human menopausal gonadotropin (hMG). Three types of treatment cycle were investigated, namely (1) cycles showing a normal ovarian response and resulting in a pregnancy; (2) cycles showing a poor response to the hMG, and (3) cycles previously showing a poor ovarian response but augmented with biosynthetic human growth hormone. Good correlations were seen between serum inhibin concentrations and serum progesterone in the luteal phase prior to buserelin (Rs = 0.68), serum oestradiol on the 8th day of hMG administration (Rs = 0.82) or the day of ovulatory trigger (Rs = 0.78), and the number of follicles greater than or equal to 14 mm on the day of ovulatory trigger (Rs = 0.71). These results show inhibin to be a good index of ovarian function in women exhibiting a range of ovarian responses to stimulation in an in vitro fertilization program.