Comparative analysis of clinical and anamnestic data from couples undergoing frozen-thawed embryo transfer in the natural and hormone replacement therapy cycle

Objective: To analyze clinical and anamnestic data of patients undergoing ART and subsequent frozen-thawed embryo transfer in the natural and hormone replacement therapy (HRT) cycle. Materials and methods: The study included 102 infertile couples with women aged from 23 to 43 years. Of these, 42 and 60 underwent embryo transfer in a natural and HRT cycle, respectively. The baseline evaluation consisted of a complete clinical and laboratory examination, assessment of the hormonal profile, and ultrasound examination. The study analyzed the results of in-vitro fertilization (IVF) and frozen-thawed embryo transfer. Results: Patients in the HRT cycle group who achieved and did not achieve pregnancy had statistically significant differences in progesterone level (p<0.001), testosterone level (p=0.02) and endometrial thickness on date of embryo transfer (p<0.001). Positive correlations were also found between endometrial thickness on the day of embryo transfer and baseline progesterone levels (p=0.04, r=0.28). In the natural cycle group, there were statistically signif icant differences between patients who achieved and did not achieve pregnancy in progesterone levels (p<0.001). Conclusion: The natural cycle and HRT cycle groups did not differ statistically significantly in pregnancy rates in frozen-thawed embryo transfer (p=0.70). High baseline progesterone levels before IVF were associated with pregnancy onset in both natural cycle and HR Tgroups, which suggests its possible association with the effectiveness of ARTprograms and requires further study. Therefore, an individualized approach to luteal phase support during cryopreserved embryo transfer in both natural cycle and HRT cycle according to serum progesterone levels may play an important role in increasing the effectiveness of ART programs.

assisted reproductive technologies, pregnancy, in vitro fertilization, infertility, embryo implantation, endometrial receptivity, implantation window, progesterone, frozen-thawed embryo transfer, cryopreservation of embryos, natural cycle, hormone replacement therapy cycle