Overweight and obesity affect the efficacy of vaginal vs. intramuscular progesterone for luteal-phase support in vitrified-warmed blastocyst transfer.

Luteal-phase support with vaginal progesterone was associated with reduced LBRs compared with intramuscular progesterone for vitrified-warmed blastocyst transfer, and the association was modified by maternal overweight/obesity. Further research is needed to better understand the mechanisms behind the association.