Effect of oral estriol on abnormal plasma FSH and LH concentrations in women with unexplained infertility; conception in a patient with elevated FSH and LH.
Estriol tablets in the daily dose of 0.25, 0.5 or 1.0 mg were administered for ten days prior to the expected ovulation in six women with unexplained, long-standing infertility, regular, apparently ovulatory cycles, and normal cyclic changes in estradiol and progesterone. Five of six had abnormal FSH and LH patterns contrasting with normal estradiol and progesterone secretion during the control cycle. There was an increase in the midcycle LH surge at two lower doses of estriol and at the highest dose there was a 7-9 day delay observed in the estradiol peak, LH surge and menstrual period in the patient with the normal control cycle. This contradicts previously published data that estriol does not suppress or delay ovulation at the dose as high as 6 mg/day. In four patients with persistently elevated LH and low FSH concentrations, there was little change in the pattern of FSH, LH, estradiol or progesterone secretion during treatment. In the last patient, who had during the control cycle plasma FSH and LH concentrations fluctuating between high normal and menopausal range, indicating "premature ovarian failure" and absence of ovarian follicles, essentially normal cyclic pattern of both gonadotropins with exception of few individual values appeared during treatment. The patient conceived during the last cycle of treatment (estriol 1.0 mg/day). Our study demonstrates that high concentrations of FSH and LH may not necessarily indicate the absence of oocytes and documents previously reported, but never documented occurrence of a conception during estrogen therapy in such a case.