Purpose: To measure the estradiol (E2) and progesterone levels on day of human chorionic gonadotropin (hCG) and to assess follicular development, pregnancy rates and IVF-ICSI outcomes comparing gonadotropin releasing hormone (GnRH) agonist and antagonist protocols.
Methods: A total 195 women were included in the study. The patients were treated with agonist or antagonist protocol according to the clinician's and patient's preference. GnRH agonist and antagonists were administered to 77 and 118 patients, respectively.
Results: Retrieved oocyte number (RON), metaphase two oocyte number (MON), E2 and progesteron levels on day of hCG, and fertilization rate were significantly higher in agonist group than antagonist group (p < 0.05). Implantation rate (IR), clinical pregnancy rate (CPR), and ongoing pregnancy rate (OPR) were significantly higher in antagonist group than agonist group (p < 0.05). However, there was no significant difference between both groups in relation with total follicle stimulating hormone (FSH).
Conclusion: GnRH agonist treatment seems to be associated with higher serum E2 and progesterone levels and resulted in lower pregnancy rates than antagonist treatment.