Progesterone Action on Endometrium of PCOS

Objective: To study the influence of metabolic factors on the action of progesterone on the endometrium of women with PCOS. Design: A prospective open-label clinical trial. Setting: Participants were recruited from an outpatient reproductive endocrinology clinic at an academic tertiary medical care center from 2014 to 2019. Subjects: To assess the sole effect of progesterone (P4) on the endometrium we studied amenorrheic (cycles\> 90 days) women with PCOS (n=23), comparing them to healthy eumenorrheic control women ( n=13). Intervention(s): All subjects underwent an endometrial biopsy (EB) in the follicular phase of the first study cycle. They were then treated with micronized P4 (400 mg/day x 10 days intravaginally) from days 14-28 of the cycle, and a second EB was performed between days 20-24 of the cycle (second phase). Main Outcome Measure(s): EB samples were analyzed under light microscopy for histomorphometric analysis.