RESUMO
AIM: To explore the clinical effect of endometrial injury (EI) on the third day of the menstrual cycle before frozen-thawed embryo transfer (frozen-thawed ET) on patients experienced two or more implantation failures. METHODS: A total of 200 patients who suffered at least two failed hormone-replacement therapies and frozen-thawed ET were randomly divided into two groups: EI group and control group (n = 100 in each group). Patients in the EI group received local EI with a Pipelle catheter on the third day of the menstrual cycle before frozen-thawed ET. Primary outcomes were live birth, clinical pregnancy and implantation rates. Secondary outcomes were biochemical, multiple and ectopic pregnancy rates and abortion rates. RESULTS: The rate of live birth in EI group (51.00%) was significantly higher than that of control group (36.00%) (P = 0.032). Clinical pregnancy and implantation rates in EI group were significantly higher comparing to control group (64.00% vs 48.00%, P = 0.023 and 46.74% vs 30.11%, P = 0.001). The rate of multiple pregnancy in EI group (37.50%) was significantly higher than that of control group (18.75%) (P = 0.031). No significant difference in ectopic pregnancy rate and abortion rate was observed between EI group and control group. CONCLUSION: Applying EI to patients experienced two or more implantation failures on the third day of the menstrual cycle before frozen-thawed ET can improve clinical outcomes.