Difference of the hormonal profile at the periovulatory phase in pregnant and nonpregnant cycles of infertile women with unexplained etiology.

Ten women with unexplained infertility, who conceived by intrauterine insemination (IUI) or timed intercourse under controlled ovarian hyperstimulation, were analyzed to investigate the difference of hormonal environment at the periovulatory phase. Forty-two cycles were divided into three groups: the pregnant cycle group, the high luteinizing hormone (LH) group (LH > or = 60 mIU/ml on day -1: the day of human chorionic gonadotropin administration) of nonpregnant cycles and the low LH group (LH < 60 mIU/ml on day -1) of nonpregnant cycles. Progesterone (P4)/estradiol (E2) ratios of the high LH group on day -1 and day 0 were significantly higher than those of each corresponding day in the pregnant cycle. On the other hand, P4/E2 ratio of the low LH group on day +1 was significantly lower. P4/E2 ratio but absolute level of each hormone showed a high indicative value for the estimation of abnormal hormonal environment. It is concluded that the P4/E2 ratio at the periovulatory phase is a good parameter to estimate the efficacy of the method for ovulation induction.