Comparison of the efficacy of different progesterone regimens in blastocyst frozen-thawed embryo transfer cycles

Aim: The progesterone’s optimal route for luteal phase support (LPS) in frozen-thawed embryo transfer (FET) cycles is controversial. This study investigates the effect of three treatment regimens of progesterone: vaginal, oral, and subcutaneous form for LPS in FET cycles. Material and Method: Blastocyst cryopreserved FET cycles utilizing vaginal, subcutaneous, or oral forms of progesterone between December 2018 and May 2020 were included. The main outcome was to compare clinical pregnancy rates (CPR), ongoing pregnancy rates (OPR), and live birth rates (LBR) in different progesterone groups. Results: A total of 434 cycles were included, of which 200 utilized vaginal, 124 utilized subcutaneous, and 110 utilized oral forms. Demographic and cycle characteristics were similar between all three groups. Compared to cycles utilizing vaginal, subcutaneous, and oral forms, CPR, OPR, and LBR differ significantly between the three groups (p-value = 0.000). Miscarriage was calculated according to the number of days after embryo transfer, and it was shown that the subcutaneous group had the lowest rate of miscarriage with 11 cases (8.8%). The highest OPR was associated with the subcutaneous group with 67 (54%), followed by the vaginal group with 92 (46%). The highest LBR was in the subcutaneous group, with 59 (47.6%) cases. The oral group was significantly less successful 29 ( 26.4%) than the subcutaneous and vaginal groups. Conclusion: Our study results showed that subcutaneous and vaginal progesterone performed better than oral progesterone for LPS in patients undergoing FET. All three forms of progesterone administration were safe and well-tolerated.