UTERINE RECEPTIVITY IN AN OOCYTE DONATION PROGRAM

Oocyte donation is a useful model for the assessment of potential fact ors affecting implantation since embryos generated are from younger oo cytes than in in-vitro fertilization programmes and are therefore expe cted to have higher and more consistent implantation rates. Transvagin al sonographic measurement of endometrial thickness, echogenic pattern and uterine artery impedance, measured as pulsatility index (PI) and resistance index (RI), were retrospectively compared in 99 recipient w omen following 117 fresh embryo transfers that resulted in 51 concepti on cycles and 66 non-conception cycles. The prevalence of a multilayer ed echogenic pattern was significantly greater (91.2%) in conception t han in non-conception (44.4%) cycles. No differences in endometrial th ickness, PI or RI were observed between conception and non-conception cycles. However, no pregnancy occurred when the PI was greater than or equal to 3.4 (sensitivity 100%). The number of days or cumulative dos e of oestrogen intake and the serum oestradiol concentration prior to progesterone administration were not different in the multilayered pat tern versus other echogenic pattern groups. The data show that it may be beneficial to await achievement of a PI < 3.4 and a multilayered pa ttern endometrium prior to embryo transfer in an oocyte donation progr amme.