Embryo implantation rates in oocyte donation: a prospective comparison of tubal versus uterine transfers.

ABSTRACT

OBJECTIVE: To compare pregnancy and implantation rates in tubal and uterine transfers during a hormonal replacement cycle in an oocyte donation program. DESIGN: Prospective randomized. PATIENTS Forty-two consecutive patients who entered an oocyte donation program. INTERVENTIONS: Twenty-two patients were assigned for uterine transfer and 20 for tubal embryo transfer (ET). RESULTS: Twenty-three pregnancies were achieved, 12 (54.5%) after uterine transfers and 11 (57.9%) after tubal transfers. Implantation rates in both groups are not significantly different (17.4% uterine transfers versus 21.5% tubal ETs). CONCLUSIONS: Our results suggest that in hormonal replacement cycles (uniform endometrial stimulation) there is no advantage in transferring embryos to the fallopian tube. Furthermore, embryo quality and endometrial receptivity appear to be significantly more important than the time of entrance of an embryo to the uterine cavity in determining its chances of implantation.