Premenstrual administration of gonadotropin-releasing hormone antagonist coordinates early antral follicle sizes and sets up the basis for an innovative concept of controlled ovarian hyperstimulation

To investigate whether premenstrual administration of a GnRH antagonist coordinates early antral follicle sizes during the subsequent follicular phase. Prospective, longitudinal study. University Hospital in France Twenty-five women, 50 cycles. On cycle day 2 (control/day 2), women underwent measurements of early antral follicles by ultrasound and serum FSH and ovarian hormones. On day 25, they received a single cetrorelix acetate administration, 3 mg. On the subsequent day 2 (premenstrual GnRH antagonist/day 2), participants were re-evaluated as on control/day 2. Magnitude of follicular size discrepancies. Follicular diameters (4.1 ± 0.9 vs. 5.5 ± 1.0 mm) and follicle-to-follicle size differences decreased on premenstrual GnRH antagonist/day 2 as compared with control/day 2. Consistently, FSH (4.5 ± 1.9 vs. 6.7 ± 2.4 mIU/mL), E 2 (23 ± 13 vs. 46 ± 26 pg/mL), and inhibin B (52 ± 30 vs. 76 ± 33 pg/mL) were lower on GnRH antagonist/day 2 than on control/day 2. Premenstrual GnRH antagonist administration reduces diameters and size disparities of early antral follicles on day 2, likely through the prevention of luteal FSH elevation and early follicular development. This simple, original approach may be used to coordinate multifollicular development in controlled ovarian hyperstimulation.