hCG day progesterone level has no impact on the frozen thawed embryo transfer cycle outcome.

Objective: To assess the association between hCG day progesterone levels and subsequent frozen-thawed embryo transfer (FET) cycle outcome in infertile women with and without polycystic ovary syndrome (PCOS).

Method: Data of 178 women who underwent FET at a university-based infertility clinic between January 2016 and December 2019 were reviewed. The study group consisted of women who had progesterone elevation (PE) during fresh controlled ovarian stimulation (COS) cycle. A sub-group analysis was also performed in PCOS and non-PCOS patients.

Results: There were no differences in clinical pregnancy (47.7 % vs. 50.7 %, p = 0.729), miscarriage (15.9 % vs. 22.4 %, p = 0.359), and live birth rates (27.3 % vs. 23.9 %, p = 0.652) following FET between women with and without PE in the fresh cycle. The results remained non-significant regarding the clinical pregnancy (46.7 % vs. 53.4 %, p = 0.549), miscarriage (13.3 % vs. 27.6 %, p = 0.133), and live birth rates (26.7 % vs. 19.0 %, p = 0.408) in participants with PCOS (n = 88).

Conclusion: hCG day progesterone level in the fresh COS cycle does not have a significant impact on the subsequent FET cycle neither in PCOS nor in non-PCOS women.