RESUMEN
OBJECTIVE: To assess the clinical effects of recombinant luteinizing hormone (LH) or low-dose recombinant human chorionic gonadotropin (hCG) supplementation administered in the midfollicular phase in microdose gonadotropin-releasing hormone analogue (GnRH-a) flare-up cycles. DESIGN: Prospective randomized study. SETTING: Private infertility clinic. PATIENT(S): A total of 170 women enrolled, with 145 women eligible for randomization. INTERVENTION(S): After randomization, 51 patients (group A) received only 600 IU of recombinant follicle-stimulating hormone (FSH) as the control group, 46 patients (group B) received 600 IU of recombinant FSH plus daily supplementation with 75 IU of recombinant luteinizing hormone, and 48 patients (group C) received 600 IU of recombinant FSH plus daily supplementation with 75 IU of recombinant hCG. MAIN OUTCOME MEASURE(S): Peak estradiol (E(2)) levels, days of stimulation with recombinant FSH, total recombinant FSH dosage, metaphase II oocytes retrieved, pregnancy rate (positive hCG levels), clinical pregnancy rate (positive fetal cardiac activity), and cancellation rates of stimulation and embryo transfer. RESULT(S): The pregnancy rates were 35.1%, 27.6% and 31.2% for groups A, B, and C, respectively. Clinical pregnancy rates were 27.1%, 27.5, and 21.8% for groups A, B, and C, respectively. There were no statistically significant differences in the age, peak serum E(2) concentration, total recombinant FSH dosage, days of stimulation with recombinant FSH, total number of metaphase II oocytes retrieved, number of embryos transferred, pregnancy rates, clinical pregnancy rates, or cancellation rates of stimulation and embryo transfer among the three groups. CONCLUSION(S): Additional exogenous LH activity in the form of either recombinant luteinizing hormone or low-dose recombinant hCG is unnecessary in microdose cycles to increase pregnancy rates.