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 effectiveness of subcutaneous estradiol pellets in donor oocyte recipients with 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 prior 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 regimens, in contrast to 11.7 +/- 1.8 mm on pellets, while estradiol levels were 674 +/- 844 and 815 +/- 706 pg/ml, respectively. The estradiol:estrone ratio on pellets was > 1. There was 1 pregnancy with early loss during 10 cycles on other estrogen regimens and 12 pregnancies during 19 cycles on pellets. The pregnancy and implantation rates were, respectively, 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 extending into the first trimester of pregnancy, a physiologic estradiol:estrone ratio, and a better endometrial response than standard estrogen regimens. Implantation and pregnancy rates are higher. This approach may be especially suitable for recipients with a poor endometrial response.