Ovarian suppression with oral contraceptive pills prior to ART: can you get too much of a “good” thing?

Abstract

Objective: Women undergoing ART are frequently placed on oral contraceptive pills (OCP) for pre-cycle ovarian suppression and to assist in patient scheduling. In our military hospital-based ART program, patients are enrolled world-wide into quarterly cycles. This often necessitates a long duration of oral contraceptive ART pre-cycle suppression (> 42 days). The objective of this study is to compare the effect of prolonged oral contraceptive pre-treatment on ART cycle outcome. Design: Retrospective Cohort Analysis. Materials and Methods: Women undergoing their first ART cycle from January 2002 to September 2002 were included for analysis. All were pre-treated with 35 microgram monophasic oral contraceptive pills. Ovarian hyperstimulation was with 40 microgram GnRH-agonist flare gonadotropin protocols (Leondires et al., 1999). All infertility diagnoses, ART cycle types, and stimulation protocols were considered. Cycle cancellation and clinical pregnancy rates (CPR) per cycle start and embryo transfer were then compared between ART cycles in which OCP pre-ART cycle pretreatment was ≤ 42 and > 42 days. Statistical significance was determined by χ2, with a p < 0.05 considered significant. Results: 327 ART cycles met criteria for inclusion in the analysis. OCP pre-treatment of ≤ 42 days (mean 31.1) occurred in 166 cycles. OCP pre-treatment of > 42 days (mean 64.6) occurred in 161 cycles. Patient age and basal FSH were not significantly different in both groups. The cycle cancellation rate was 9.6% in women treated ≤ 42 days vs. 25.5% in women treated > 42 days (p < 0.05). The CPR per cycle start was 40.4% in women treated ≤ 42 days vs. 34.8% in women treated > 42 days. CPR per transfer was 44.7% in women treated ≤ 42 days vs. 46.7% in women treated > 42 days. Cancellations in both groups were restricted to poor ovarian response. The significant differences are noted in Table 1. Tabled 1 Conclusion: Prolonged oral contraceptive pill use for pre-cycle ovarian suppression increases the cancellation rate in ART, presumably by decreasing ovarian response. In patients who achieve embryo transfer, however, pregnancy rates are not affected.