SUBCUTANEOUS ESTRADIOL PELLETS FOR ENDOMETRIAL PREPARATION IN DONOR OOCYTE RECIPIENTS WITH A POOR ENDOMETRIAL RESPONSE

Purpose: The purpose of this study was to evaluate the clinical effect iveness of subcutaneous estradiol pellets in donor oocyte recipients w ith an inadequate endometrial response. Methods: The subjects were 13 women with ovarian failure and a maximal endometrial thickness <10 mm on standard estrogen regimens, as demonstrated during mock and/or prio r oocyte donation cycles. They underwent pellet implantation (100-250 mg of estradiol) 6-13 weeks before oocyte donation. Results: Maximal ( mean +/- SD) endometrial thickness was 8.7 +/- 1.5 mm on standard regi mens, in contrast to 11.7 +/- 1.8 mm on pellets, while estradiol level s were 674 +/- 844 and 815 +/- 706 pg/ml, respectively. The estradiol: estrone ratio on pellets was >1. There was I pregnancy with early loss during IO cycles on other estrogen regimens and 12 pregnancies during 19 cycles on pellets. The pregnancy and implantation rates were, resp ectively, 63 and 27% on pellets and 41 and 14% on standard regimens in historical controls. Conclusions: We conclude that estradiol pellets after a single administration provide constant estradiol levels extend ing into the first trimester of pregnancy, a physiologic estradiol:est rone ratio, and a better endometrial response than standard estrogen r egimens. Implantation and pregnancy rates are higher: This approach ma y be especially suitable for recipients with a poor endometrial respon se.