Analysis of the gonadotropin surges in patients with premature ovarian failure undergoing steroid replacement cycles

Ovarian steroids regulate pituitary gonadotropin secretion in normal cycles. This regulation has also been demonstrated in hypogonadal women receiving exogenous drugs, and has been suggested in women with premature ovarian failure receiving cycles of steroid replacement for oocyte donation. The purpose of this study was to analyse the gonadotropin surges in patients with premature ovarian failure using different experimental protocols. Those protocols were planned to induce the surges with different combinations of estradiol valerate and progesterone. According to the first protocol, a typical sequential administration of estradiol valerate and progesterone was given as a control. Maximal estradiol levels were detected on day 12 of the artificial cycle. The negative feed-back of estradiol was evident, with a significant (p less than 0.05) reduction of FSH and LH from the initial values. The positive feed-back showed a moderate LH surge in 6 out of 8 patients. In addition, a mild FSH increase was detected in 4 women. Both surges occurred on day 15 and were coincident with a decreased estradiol valerate and increased progesterone intake. A second protocol was scheduled for 5 patients in order to identify a real LH surge. High-dose estradiol valerate administration was maintained and progesterone was not administered. The LH surge clearly appeared on day 15 in all subjects, but the peak value was again moderate. The third protocol was designed in order to demonstrate a real FSH surge in 4 patients. Progesterone administration was advanced by 5 days.(ABSTRACT TRUNCATED AT 250 WORDS)