Abstract: Objectives To compare and analyze the effect of two controlled ovarian stimulation (COH) protocols (Modified ultra-long down-regulation protocol vs. conventional long down-regulation protocol) for In Vitro Fertilization / Intracytoplasmic Sperm Injection - Embryo Transfer (IVF/ICSI-ET) treatment in infertility patients with Polycystic Ovarian Syndrome (PCOS).Methods 132 IVF/ICSI-ET cycles utilizing modified ultra-long down-regulation protocol and 588 IVF/ICSI-ET cycles underwent conventional long down-regulation protocol during August 2008 to December 2009 were retrospectively analyzed. Several key parameters of the two COH protocols, including: fertilization and cleavage rate, clinical pregnancy rate, live birth rate, abortion rate, treatment duration and therapeutic expenses etc. were compared and analyzed. Results In modified ultra-long down-regulation protocol, the fertilization and cleavage rate, clinical pregnancy rate and implantation rate were significantly increased, P<0.001, as well for the live birth rate (P<0.05), the abortion rate (P<0.05) and the progesterone level on the day of HCG injection were decreased (P<0.001). In the mean while, the treatment duration was shortened (P<0.001), and treatment cost were reduced (P<0.001), when compared to conventional long protocol. Conclusion Modified super-long protocol plus hMG for PCOS infertile patients saved the therapeutic cost and raised the success rate of ART.

Key words: PCOS, ultra-log down-regulation protocol, IVF-ET