Endometrial Transcript Profile with Progesterone After Post-ovulatory Mifepristone

Objective: To determine the effect of progesterone supplementation on the mid-secretory endometrial transcript profile after postovulatory administration of mifepristone. Design: A randomized, double-blind, placebo-controlled study. Setting: Tertiary academic medical center Subjects: A total of 9 Hispanic women of proven fertility who had been surgically sterilized. Interventions: Participating women received a single dose of mifepristone 200mg 48 hours after the LH peak (LH+2, LH+0=LH peak). Endometrial samples were obtained on LH+7 after vaginal administration of micronized progesterone (600mg/day) for 3 days (LH+3 to LH+5). Each woman contributed with one cycle treated with placebo and another with progesterone (group A). Additionally, endometrial samples were obtained on LH+7 from subset of 4 women who did not receive mifepristone; with each one contributing with one cycle treated with vaginal progesterone supplementation or placebo as a reference (group B). Endometrial thickness, circulating progesterone levels, and endometrial histology were also documented in all cycles. RNA-seq was used to identify genes whose transcript levels significantly changed by the administration of progesterone versus placebo, with postovulatory administration of mifepristone. The transcript profiles of these genes were further evaluated in the endometrial samples from group B.