Objective: This study aimed to evaluate the effect of three days of GnRH antagonist pretreatment on the pregnancy outcomes of women with polycystic ovarian syndrome (PCOS) on GnRH antagonist protocols for IVF/ICSI.
Methods: Fifty women with PCOS in the control group received conventional antagonist protocols, starting on day 2 of the cycle. In the pretreatment group (n=38), a GnRH antagonist was administered from day 2 of the menstrual cycle for three days.
Results: Controlled ovarian stimulation (COS) duration and gonadotropin dosages were similar in both groups. The number of metaphase II (MII) oocytes, 2PN oocytes, embryos, along with implantation and clinical pregnancy rates, were higher in the pretreatment group when compared with controls, although the increment was not significant (P value ≥0.05). The chemical pregnancy rate was significantly higher in the pretreatment group. The rate of OHSS was significantly lower in the pretreatment than in the control group.
Conclusion: Women with PCOS offered early follicular phase GnRH antagonist pretreatment for three consecutive days had significantly fewer cases of OHSS and higher chemical pregnancy rates. There were trends toward greater numbers of MII oocytes, 2PN oocytes, and embryos, and higher clinical pregnancy rates in the pretreatment group.
Keywords: assisted reproductive technology; gonadotropins; polycystic ovarian syndrome.