Effects of endometrial injury on frozen‐thawed blastocyst transfer in hormone replacement cycles

Aim To evaluate whether local endometrial injury would improve the pregnancy rates after frozen-thawed blastocyst transfer in cycles with hormone replacement. Methods Seventy-seven patients who were aged <40 years with a history of at least three unsuccessful embryo transfers and who underwent frozen-thawed blastocyst transfer during hormone replacement cycles between February and June, 2013 were studied. They were allocated into two groups based on the last digit of their clinical record number: an experimental group (n=22), excluding patients who withheld consent or who were unable to undergo treatment, and a control group (n=55). In the experimental group, the endometrium was scratched once with an endometrial sampler during the luteal phase of the cycle preceding the embryo transfer. Results There was no significant difference in the baseline characteristics between the groups. The clinical pregnancy rate was 6% in the experimental group and 22% in the control group. Among these, the ongoing pregnancy rate was 100% in the experimental group and 50% in the control group. Conclusion Endometrial injury might increase the pregnancy rates after frozen-thawed blastocyst transfer and decrease the risk of miscarriage in patients with a history of unsuccessful embryo transfers.