Ovarian cyst formation following GnRH agonist administration in IVF cycles: incidence and impact.

BACKGROUND The formation of functional ovarian cysts has been recognized as one of the side effects of GnRH agonist administration. The formation of cysts during IVF treatment may be of no clinical significance or may negatively influence its outcome. The objective of this study was to determine the incidence of ovarian cyst formation following GnRH agonist administration and to examine their effect on IVF outcome. METHODS A prospective study of 1317 IVF patients who developed one or more functional ovarian cysts of >or=15 mm following GnRH agonist treatment was performed. Transvaginal ultrasonographic-guided cyst aspiration was carried out in 76 randomly allocated patients out of 122 patients who were found to have functional ovarian cysts before starting ovarian stimulation with gonadotropins. RESULTS The incidence of follicular cyst formation was 9.3%. Cyst cycles in comparison with non-cyst cycles had significantly elevated day 3 basal FSH (mean+/-SD of 8.3+/-3.2 versus 5.3+/-2.6 mIU/ml, P<0.05) and required more ampoules of gonadotropins (46.3+/-16.5 versus 35+/-14.6, P<0.01). Furthermore, they showed a statistically significant decrease in the quality and number of oocytes retrieved, fertilization rate, number and quality of embryos, implantation and pregnancy rates, with a significant increase in cancellation and abortion rates. Patients with bilateral cysts had a significantly lower number of oocytes and embryos retrieved, with a lower proportion of metaphase II oocytes. They also had a higher proportion of poor quality embryos. Cyst aspiration was not associated with a significant difference in the above parameters. CONCLUSIONS The incidence of cyst formation during GnRH agonist treatment is lower than previously reported. In such cases, the quality of oocytes and embryos were significantly compromised, with a significant increase in the cycle cancellation rate and a decrease in the implantation and pregnancy rates. Neither conservative management nor cyst aspiration improved the IVF outcome.