Vuong LN, Pham TD, Le KTQ, et al. - In this prospective cohort study, researchers investigated whether improved pregnancy outcomes during frozen embryo transfer (FET) cycles could be achieved with the addition of oral dydrogesterone to vaginal progesterone as luteal phase support vs vaginal progesterone alone. This study involved 1,364 females receiving IVF with FET. The luteal support regimen comprised either vaginal micronized progesterone 400 mg twice daily plus oral dydrogesterone 10 mg twice daily (second part of the study) or vaginal micronized progesterone 400 mg twice daily (first 4 months of the study). Findings revealed a higher live birth rate as well as a lower miscarriage rate in relation to luteal phase support with oral dydrogesterone added to vaginal progesterone vs vaginal progesterone alone.