Reproduction Abstracts

Introduction: Mechanical endometrial injury (i.e. endometrial scratch) in the cycle preceding ovarian stimulation for IVF has been proposed to improve implantation in women with unexplained recurrent implantation failure (RIF).

During the implantation window, there is a cross-talk between the embryo and endometrium to allow attachment, adhesion and invasion of the embryo. Endometrial scratch (ES) is suggested to induce changes in the immune system in the uterus which stimulate natural killer cells, which are thought to be a key part of implantation.

Some studies have demonstrated an increase in pregnancy rates among women who have had an ES with a history of RIF. Others have failed to demonstrate benefit. Conclusions regarding the efficacy of the procedure are limited by heterogeneity between studies.

We aimed to assess outcomes in women who have undergone an ES during IVF treatment for RIF at the Fertility Exeter clinic from January 2015–2016.

Methods: A retrospective review of data collected on IVF treatment cycles undertaken at Fertility Exeter from January 2015 to January 2016. Sub-analysis separating frozen embryo transfer cycles and fresh embryo transfer cycles was also performed. Scratches were performed in the preceding treatment cycle according to the clinic protocol.

Results: For completed treatment cycles (i.e. from ovulation induction to embryo transfer) clinical pregnancy rates were 35.1% among those who had an ES, compared to 30.3% who did not undergo ES. In those who had a frozen embryo transfer (FET) clinical pregnancy rates were 54.5% in the ES group, versus 32.3% in those who did not have a scratch. For fresh embryo transfers, clinical pregnancy was achieved in 26.9% of those who did have ES compared to 29.8% of those without ES. The difference between these groups was not found to be statistically significant. There was no difference in the rate of miscarriage between treatment groups.