Comparison of pregnancy rates of modified natural cycles and hormone replacement therapy cycles in frozen embryo transfer cycles with embryo transfer at blastocyst stage: Retrospective study

Comparison of Pregnancy Rates of Modified Natural Cycles and Hormone Replacement Therapy Cycles in Frozen Embryo Transfer Cycles with Embryo Transfer at Blastocyst Stage: Retrospective Study Frozen embryo transfer has grown rapidlyin recent years. Optimization of endometrial preparation before frozen embryo transfer is important. Endometrial preparation for frozen embryo transfer can be accomplished with a natural cycle or a cycle of hormone replacement therapy (HRT). To date, many studies have compared endometrial preparation methods for frozen embryo transfer, but the results of these studies are inconsistent. In this study, patients between the ages of 20 and 37 who applied to the Reproductive Techniques Clinic of Akdeniz University Faculty of Medicine and underwent frozen embryo transfer were retrospectively analyzed. A total of 30 modified natural cycle protocols and 30 HRT cycle protocols were applied; Positive hCG value, biochemical pregnancy rate, clinical pregnancy rate, abortion rate and ongoing pregnancy rates were examined after frozen embryo transfer in these two group. These rates were 76.7%, 8.7%, 91.3%, 17.4%, and 82.6% in the modified natural cycle group, In the HRT cycle group, it was 63.3%, 5.3%, 94.7%, 15.8%, 84.2%. As a result, no superiority was found between the two types of endometrial preparation methods. Keywords:Frozen embryo transfer, endometrial preparation, clinical pregnancy