The use of the donor oocyte program to evaluate embryo implantation

Pregnancy rates (PRs) are generally higher in most IVF programs when embryos derived from donor oocytes are transferred compared to the PRs of women undergoing IVF-ET. DeZiegler et al., using the transfer of frozen embryos (either patient or donor derived) in natural cycles, found a higher PR following donor oocyte derived ET and thus concluded that the lower PR in the non-donor cycles was not related to the controlled ovarian hyperstimulation (COH) regimen. Their data thus suggested the improved PR with donor embryos may be related to better quality oocytes used for recipients; however, a more receptive endometrium in the oocyte recipients could also explain the data. The studies presented herein further evaluated the latter hypothesis of improved endometrial environment for recipients by comparing PRs in donors vs recipients in a shared oocyte program. Also the study would determine if endometrial echo patterns (EP) and/or thickness (ET) help predict better PRs as they do in stimulated cycles. Finally studies would be performed to compare PRs in older vs younger oocyte recipients to see if there may be a uterine senescence in humans as in other animals and to see if age has an adverse effect on the endometrium as evidenced by sonographic studies. Study 1 compared the clinical PRs in donors vs recipients in a shared program from 1/1/92 to 12/31/92. PR for donors was 23.6% (17 pregnant in 72 transfers) compared to 34.6% for recipients (26/75). Mean age of the donors was 32 compared to 39.8 for recipients. If recipients > 40 were eliminated the PR for recipients was 44.1% (15/34). Study 2 evaluated PRs according to ET and EP in 58 transfers using donor oocytes (44 patients). There were only 2 clinical pregnancies of 22 transfers (9%/cycle) when ET was < 10 mm at the time of the donor's hCG injection compared to 14 pregnant of 36 transfers (38.7%) when ET was > or = 10 mm (p < 0.01). However, there were no differences in PR when the endometrium compared to myometrium was hypoechogenic, isoechogenic, or hyperechogenic. The respective PRs were 16.7% (1/6), 31% (9/39) and 26.1% (6/23). Study 3 evaluated PRs in donor oocyte recipients according to age (< 40 vs > or = 40 years). After evaluating PRs after the first 58 ETs to recipients of shared oocytes we found a much lower PR in women > or = 40 (2/23, 8.6%/cycle) vs 14/55 (25.4%) in those < 40.(ABSTRACT TRUNCATED AT 400 WORDS)