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.