Comparison among different ovarian stimulation regimens for assisted procreation procedures in patients with endometriosis

The objective of our study was to establish the most adequate ovarian stimulation regimen for assisted procreation in endometriotic patients. It consisted of a retrospective analysis comparing the use of the gonadotrophin-releasing hormone analogue (GnRHa) buserelin either for 3 months or for 3 weeks and continued with ovarian stimulation with human menopausal gonadotrophin (HMG), and the use of clomiphene citrate in association with HMG for in-vitro fertilization (IVF) and embryo transfer, gamete intra-Fallopian transfer (GIFT) and zygote intra-Fallopian transfer (ZIFT). A total of 145 patients with endometriosis in 174 cycles were divided into two groups according to the revised American Fertility Society staging of the disease (group A, stages 1 and 2; group B, stages 3 and 4). The use of GnRHa significantly increased the number of oocytes retrieved. GnRH analogues for 3 months gave the highest fertilization rate for groups A and B. The cleavage, pregnancy and delivery rates, although higher in the groups treated with analogues, did not reach statistical significance. A higher number of patients had an embryo transfer in the groups treated with GnRHa (P < 0.05). Treatment with GnRHa for either 3 months or for 3 weeks proved to be more efficient than clomiphene citrate-HMG for assisted procreation procedures in patients with endometriosis.