Microdose follicular phase gonadotropin-releasing hormone agonist (GnRH-a) compared with luteal phase GnRH-a for ovarian stimulation at in vitro fertilization.

OBJECTIVE: To compare an ovarian stimulation protocol using microdose follicular phase GnRH agonist (GnRH-a) and oral contraceptive (OC) pills to a luteal phase GnRH-a protocol.

DESIGN: Retrospective analysis.

SETTING: University affiliated IVF program.

PATIENT(S): One hundred seventy patients who underwent IVF and ET in 1996.

INTERVENTION(S): Patients were assigned to either a midluteal start of leuprolide acetate (LA) 1 mg/d, reduced to 0.5 mg/d after addition of gonadotropins (LUT), or OC pills until cycle day 0 followed by 20 microg of LA every 12 hours on cycle day 3 with addition of gonadotropins on cycle day 5 (MICRO).

MAIN OUTCOME MEASURE(S): Number of FSH ampules, days of stimulation, peak E2, and number of oocytes retrieved.

RESULT(S): There were no statistically significant differences in the main outcome measures between the two groups using an age-matched ANOVA. Clinical pregnancy rate per cycle start was not statistically different (LUT = 54%, and MICRO = 37%). The cancellation rate was significantly higher in the MICRO group (22.5% vs. 8.2%).

CONCLUSION(S): Given the higher cancellation rate in the microdose group, a randomized clinical trial is required to determine the possible benefit of a lower dose of GnRH-a in patients with normal ovarian function.