Vaginal versus intramuscular progesterone in oocyte donation replacement therapy

Vitrified blastocyst transfer cycles with the use of only vaginal progesterone replacement with Endometrin have inferior ongoing pregnancy rates: results from the planned interim analysis of a three-arm randomized controlled noninferiority trial

“…Endometrin at 200 mg twice daily also yielded higher trough levels than supplementation dosing (100 mg twice daily) (43). Furthermore, there is ample precedent in the literature regarding the safe use of vaginal micronized P at doses higher than the FDA-approved Endometrin supplementation dose of 300 mg/d (including up to 800 mg/d) as well as in combination with intramuscular P in oil (23,25,29,(42)(43)(44)(45)(46)(47).…”