Background: Progesterone (PG) is an essential hormone in the process of implantation and pregnancy maintenance. Frozen-thawed embryo transfer (FET) is being performed worldwide. This study was designed to investigate whether serum progesterone levels on the day prior to day 5 frozen-thawed embryo transfer (FET) to hormonally prepared endometrium correlates with pregnancy outcomes. Materials and Methods: A single center longitudinal observational study was conducted at an infertility center over a period of three months from October 2022 to December 2022. The study participants were the patients attending the infertility center who satisfied the inclusion and exclusion criteria. A total of 30 participants were included in this study. Serum progesterone levels were measured on the day of starting the progesterone (P0) and on day four (P4), the day prior to embryo transfer. Data analysis was conducted using SPSS version 21.
Results: The mean (SD) age in those who had positive pregnancy outcome was 34.22 (1.26) years and in those who had negative pregnancy outcomes was 39.92 (2.11) years and the difference was significant (P = 0.001). The mean (SD) serum progesterone levels in those who had positive pregnancy outcome at day 0 was found to be 0.61 (1.19) ng/ml and in those who had negative pregnancy outcomes was 0.28 (0.27) ng/ml but, the difference was not significant (P = 0.347). The mean (SD) serum progesterone levels in those who had positive pregnancy outcome at day 4 was found to be 10.84 (8.13) ng/ml and in those who had negative pregnancy outcomes was 8.13 (3.81) ng/ml and the difference was significant (P = 0.039).
Conclusion: Pregnancy loss increases with age and serum progesterone measurements at day 4 prior to embryo transfer could be used to assess pregnancy outcomes in frozen-thawed embryo transfer (FET) technique of infertility treatment. Monitoring of serum PG levels can be done for diagnosing potential luteal support defects before performing FET with artificial cycle (AC).