Injury to the endometrium prior to the frozen-thawed embryo transfer cycle improves pregnancy rates in patients with repeated implantation failure.

Aim: This retrospective cohort study evaluated the effectiveness of injury to the endometrium prior to the frozen-thawed embryo transfer (FET) cycle in patients with repeated implantation failure (RIF) in our clinic.

Methods: Included in this study were 173 patients, aged ≤ 41 years, who failed to become pregnant after repeating fair and/or good embryo transfer more than twice between February 2012 and February 2015. The patients were divided into three groups: Group A (n = 38) underwent soft curettage to the endometrium twice, prior to the FET cycle; Group B (n = 45) underwent hysteroscopy prior to the FET cycle, with no significant factors, such as endometrial polyp; and Group C (n = 90) was the no-treatment group.

Results: The clinical pregnancy rate per transfer was found to be statistically significant between Group A at 42.1% (16/38) and Group C at 22.2% (20/90). The crude and adjusted odds ratios (OR) were 2.55 and 2.49 (95% confidence intervals 1.13-5.78, P = 0.03 and 1.01-6.17, P = 0.048) respectively. Group B with only hysteroscopy had a higher pregnancy rate of 35.6% (16/45) than Group C, but showed no statistical significance (P = 0.103).

Conclusion: These results suggest that injuring the endometrium has a positive effect on pregnancy.