Effect of blood and mucus on the success rates of embryo transfers

Abstract Objectives To provide information about the effects of blood and mucus on the embryo transfer (ET) catheters after transfer on embryo transfer outcomes. Study design Retrospective analysis of 8311 ultrasound-guided embryo transfers performed in a single center. In 6897 cases (82.9%), there were no blood on the catheter after ET, 1168 transfers were associated with mild blood (14.1%), 33 transfers with moderate blood (0.4%) and 213 transfers with severe blood (2.6%). A total of 6162 transfer catheters were free of mucus (74.8%), whereas mucus was detected on 2081 catheters (25.2%). Results The implantation rate (IR) was highest in the group with no blood on the transfer catheter, and lowest in the group with severe blood on the catheter. The clinical pregnancy rate (CPR) was lowest in the group with severe blood on the catheter. The presence of mucus on the catheter was found to have no effect on IR, CPR, biochemical pregnancy rates, miscarriage rates and live birth rates. Conclusions This study showed decreased IR, CPR and live birth rates in ETs associated with blood on the catheter. Mucus on the catheter appeared to be a simple contamination in this study and pregnancy rates remained unaffected.