Pretreatment with an oral contraceptive is effective in reducing the incidence of functional ovarian cyst formation during pituitary suppression by gonadotropin-releasing hormone analogues.

PURPOSE

Our purpose was to assess the effect of pretreatment with oral contraceptives (OCs) on the formation of functional ovarian cysts during pituitary suppression with gonadotropin-releasing hormone (GnRH) agonists, subsequent follicular development, and pregnancy rates.

METHODS

A retrospective case-controlled study of 31 in vitro fertilization (IVF) patients, all of whom in a previous cycle had commenced the long protocol of GnRH-agonist (Buserelin) in the early follicular phase and were pretreated in a subsequent cycle with 2 weeks of an OC containing 30 micrograms of ethinyl estradiol and 150 micrograms of desogestrel prior to GnRH-agonist administration, was undertaken. Follow-up visits were arranged after a minimum of 11 days of GnRH-agonist administration and weekly thereafter until pituitary suppression was achieved.

RESULTS

Cysts were detected in 16 (51.6%) of the 31 patients not pretreated with OCs, and in 0 (0%) of the 31 patients pretreated with OCs (odds ratio = 67.1; 95% confidence interval = 5.6-350.7). Patients pretreated with OCs achieved pituitary suppression more rapidly (median difference = 4 days; 95% confidence interval = 2-7) and had comparable gonadotropin requirements and pregnancy rates.

CONCLUSIONS

Pretreatment with OCs prior to pituitary suppression in the early follicular phase decreases ovarian cyst formation, without an apparent effect on subsequent follicular recruitment or pregnancy rates.