Flexible GnRH antagonist protocol vs. long GnRH agonist protocol in patients with polycystic ovary syndrome treated for IVF: comparison of clinical outcome and embryo quality.

Objectives: Polycystic ovary syndrome (PCOS) is a common endocrine disorder, primarily affecting women of the reproductive age. The aim of the study was to assess the clinical efficacy and embryo quality in flexible gonadotropin-releasing hormone (GnRH) antagonist protocol in comparison to the long GnRH agonist protocol in PCOS women undergoing in vitro fertilization (IVF). Material and methods: This prospective, randomized study was conducted at the Department of Gynecology and Obstetrics, Clinical Center Nis, Serbia, between 2013 and 2014. The treatment included either a flexible GnRH antagonist protocol (n=45, antagonist group) or a long GnRH agonist protocol (n=45, agonist group). Results: The length of the stimulation, total amount of gonadotropins used, as well as the average number of the aspirated and mature oocytes were higher in the agonists group. The endometrial thickness was also greater in the agonists group. A higher number of Class I and Class IV embryos were obtained after the agonist treatment and higher number Of Class II and Class Ill embryos were obtained after the antagonist treatment. Pregnancy, implantation, and miscarriage rates were comparable between the groups. Conclusions: The GnRH antagonist protocol in PCOS patients has a pregnancy rate comparable to that of the GnRH agonist protocol. Since this protocol has a lower rate of complications and is more convenient for patients, we believe that the GnRH antagonist protocol should be used as the first-line treatment for PCOS patients in an IVF program.