Bleeding during transfer is the only parameter of patient anatomy and embryo quality that affects reproductive outcome: a prospective study.

There is very little information available regarding the relevance of the position of embryo replacement during ET and the different anatomic characteristics of the recipient in the transfer process and on the result of assisted reproduction techniques. We prospectively analyzed, using multivariate regression analysis, 375 ETs, 177 of which were from donated oocytes and 198 from patients' own oocytes, and we found no effect of the anatomic characteristics of the uterus on the chances of achieving pregnancy when data were analyzed according to patient age and embryo quality. Interestingly, there was a significant decrease in pregnancy rates when blood was present in the catheter after the procedure, which was confirmed in all treatments.