Progesterone support for frozen embryo transfer: Intramuscular versus vaginal suppository demonstrates no difference in a cohort

OBJECTIVE: To evaluate pregnancy rates based on the route of progesterone replacement in frozen embryo transfer (FET) cycles. STUDY DESIGN: A randomized controlled trial and retrospective analysis. In the randomized group 76 FET cycles were randomized. In the retrospective group 508 FET cycles were reviewed. Intramuscular (IM) progesterone in oil 100 mg daily or oral micronized progesterone prior to transfer followed by compounded vaginal progesterone 200 mg 3 times daily (OV). The main outcome measure was the clinical pregnancy rate (CPR). RESULTS: Baseline characteristics did not vary between groups in either cohort. In the randomized group there were no significant differences in CPR (31.43% vs. 21.05%) or live birth rate (LBR) (31.43% vs. 18.92%) for IM and OV progesterone replacement, respectively. In the retrospective cohort patients there were also no significant differences in CPR (35.56% vs. 32.35%) or LBR (32.23% vs. 28.51%) for the IM and OV progesterone replacement groups, respectively. CONCLUSION: This study demonstrates that either OV or IM progesterone is effective for luteal phase support for FETs.