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

Performing the embryo transfer: a guideline

“…In contrast to the RCT (70), meta-analysis (114), the recent large Australian cohort study (109), and five other cohort studies showing no adverse association between pregnancy rates and blood on the withdrawn embryo transfer catheter, eight other cohort studies (44,106,112,(117)(118)(119)(120)(121) demonstrated an opposite finding. A 2002 cohort study of 640 IVF-ICSI cycles showed that clinical pregnancy rate was significantly (P< .01) higher when there was no blood during transfer vs with blood.…”

Improvement in pregnancy rate by removal of cervical discharge prior to embryo transfer in ICSI cycles: A randomised clinical trial

“…In such situations, cervical manipulation using a cotton swab may lead to mechanical injury and a bloody discharge. During ET, blood from the endocervix may be drawn into the uterus and interfere with embryo implantation 17,18 . However, Moragianni et al.…”