The significance of delayed suppression using buserelin acetate and recombinant follicle-stimulating hormone in a long protocol in vitro fertilization program

Objective: To determine whether the time taken to achieve ovarian suppression has an impact on ovarian responsiveness and the outcome of IVF-ET. Design: Retrospective analysis. Setting: An assisted reproduction unit at a university center. Patient(s): Patients undergoing a long protocol of IVF-ET that included buserelin acetate therapy initiated on day 2 of the cycle and recombinant FSH. Intervention(s): Patients were divided into two groups according to the duration of buserelin acetate therapy required to achieve pituitary and ovarian suppression (group 1 = 2 weeks, n = 172; group 2 = ≥3 weeks, n = 337). Main Outcome Measure(s): Number of recombinant FSH ampules administered, duration of ovarian stimulation (days), ovarian response, and IVF outcome. Result(s): The patients in group 2 had lower mean E 2 levels after 5 days and 9 days of stimulation than the patients in group 1. The number of recombinant FSH ampules administered and the number of days of stimulation required were higher in group 2 than in group 1. These differences were prominent in the subgroups of older patients (≥36 years) and patients who had no evidence of polycystic ovaries on ultrasound examination. The number of oocytes retrieved and fertilized, the cancelation rate, and the pregnancy rate were similar in the two groups. Conclusion(s): Prolonged administration of a GnRH agonist to achieve suppression leads to a reduced ovarian response, particularly in women ≥36 years of age, but does not affect the success rate of IVF-ET.