PURPOSE: To investigate if duration of estrogenic endometrial stimulation can affect recipient pregnancy rate in an ovum donation program. METHODS: Each recipient received micronized 17 beta-estradiol orally in a steadily increasing dosage from 2 to 6 mg daily over a period of time varying from 5 to 76 days until oocyte were available for donation. Recipients (520 patients for a total of 835 transfer cycles) were retrospectively divided into five groups depending on the duration of E2 administration. RESULTS: No significant difference was seen in pregnancy and implantation rates between groups. There was a higher number of miscarriages in Group A (41%), p < 0.05 vs. Group B (15%), and vs. Group E (1%). Age, number of pregnancies and miscarriages, or implantation rate in donors (327 women aged < 35 years) were similar in all the five groups. CONCLUSIONS: Endometrial receptivity is tolerant to a wide duration of E2 treatment (until 2 months), while waiting for oocytes available for donation, but best results are achieved with a treatment range of 11 to about 40 days.
PURPOSE: To investigate if duration of estrogenic endometrial stimulation can affect recipient pregnancy rate in an ovum donation program. METHODS: Each recipient received micronized 17 beta-estradiol orally in a steadily increasing dosage from 2 to 6 mg daily over a period of time varying from 5 to 76 days until oocyte were available for donation. Recipients (520 patients for a total of 835 transfer cycles) were retrospectively divided into five groups depending on the duration of E2 administration. RESULTS: No significant difference was seen in pregnancy and implantation rates between groups. There was a higher number of miscarriages in Group A (41%), p < 0.05 vs. Group B (15%), and vs. Group E (1%). Age, number of pregnancies and miscarriages, or implantation rate in donors (327 women aged < 35 years) were similar in all the five groups. CONCLUSIONS: Endometrial receptivity is tolerant to a wide duration of E2 treatment (until 2 months), while waiting for oocytes available for donation, but best results are achieved with a treatment range of 11 to about 40 days.