Ovarian response and pregnancy outcome related to midfollicular LH levels in down-regulated women undergoing assisted reproduction

OBJECTIVE: To assess ovarian response and pregnancy outcome related to midfollicular luteinizing hormone (LH) levels in normogonadotropic women down-regulated with gonadotropin-releasing hormone-agonist (GnRH-a) (daily and depot) during an assisted reproduction cycle. STUDY DESIGN: In a prospective randomized trial, 50 women were down-regulated with leuprorelin, 0.5 mg/d subcutaneously (group A) and 50 with leuprorelin, 3.75 mg depot (group B), prior to ovarian stimulation with recombinant follicle-stimulating hormone (FSH). Midfollicular serum LH levels < or = 0.5 mIU/mL (subgroups A1 and B1) versus > 0.5 mIU/mL (subgroups A2 and B2) were considered. A comparative analysis was carried out on the clinical effects (duration of stimulation, total FSH dose, number of oocytes retrieved and pregnancy rate). RESULTS: Maximum estradiol levels and pregnancy rates were higher in subgroups A2 and B2, with LH > 0.5 mIU/mL. No differences were observed in the cumulative amount of gonadotropin used, number of oocytes retrieved or fertilization rate. CONCLUSION: When FSH only is used for ovarian stimulation, very low LH serum concentrations in normogonadotropic women profoundly suppressed with GnRH-a, especially if given as a depot, may adversely affect in vitro fertilization outcome.