Estradiol and progesterone replacement regimens for the induction of endometrial receptivity.

Overview

Initiation of pregnancy in premature ovarian failure patients by use of donated oocytes fertilized in vitro requires establishment of a normal endometrial environment. We compared administration of estradiol (E2) and progesterone (P) by polysiloxane vaginal rings versus oral micronized E2 and P vaginal suppositories in 10 such patients. Serum E2 levels were similar between groups and similar to normally-cycling controls. With vaginal administration of E2, a burst effect was noted, with marked elevation 1 hour after insertion. The pattern with oral administration was more consistent, although marked conversion to estrone occurred. The P cylinder and suppositories delivered similar levels, with diminution of P in some patients with the cylinder. Despite apparent limitations, endometrial histology was normal after each cycle; both groups achieved pregnancies. Administration of E2 and P by polysiloxane vaginal rings achieved hormonal levels similar to oral micronized E2 and P vaginal suppositories. Endometrial biopsies after the stimulated cycle were appropriately mature.