Follicle stimulating hormone levels on cycle day 3 predict ovulation stimulation response

Aim To determine the value of basal follicle stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E₂) levels on cycle day 3 in predicting the ovulation stimulation response in patients receiving exogenous gonadotropins for in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT).Methods One hundred eleven consecutive females with infertility due to various etiologies were investigated. Cycle day 3 serum levels of FSH, LH, and E₂ were determined prior to ovulation induction with a combination of clomiphene citrate and human gonadotropins. Follicular growth was monitored ultrasonically, and when appropriate, oocytes were recruited, counted, graded, and then used, as prearranged, for either IVF or GIFT. Basal hormone levels were compared to the peak E₂ concentration, the number of follicles aspirated, and the number of preovulatory oocytes recovered following drug therapy. Details of resulting pregnancies were also recorded.Results Patients with low basal FSH levels (<11.5 mIu/ml) yielded a higher mean number of preovulatory oocytes than those with high values (>11.5 mIu/ml), i.e., 6.7 oocytes per cycle vs 2.5 oocytes (P < 0.001). In the low group 97% of cycles yielded more than three fertilizable oocytes compared to 42% in the high group (P < 0.5). There were 16 term pregnancies (16%) in the low group and 1 (8.3%) in the high group. Basal LH and E₂ levels did not improve on the ability to distinguish between different populations of infertile females who responded differently to ovulation induction.Conclusion Cycle day 3 FSH levels are predictive of the ovulation response and probability of pregnancy in stimulated cycles and can be of value in patient selection and counseling in IVF and GIFT programs.