Vaginally administered estroprogestinic decreases serum inhibin A and inhibin B levels and reduces endometrial thickness.

Objective: Serum levels of inhibin A, inhibin B, FSH, and LH were measured in healthy volunteers before and during oral or vaginal estroprogestinic administration. In addition, the effect on endometrial thickness and on follicular growth pattern were also assessed by vaginal ultrasound.

Design: Prospective study.