To evaluate if local endometrial injury (endometrial scratch)
could improve the rates of clinical pregnancy and ongoing pregnancy after frozen-thawed blastocyst transfer in hormone replacement cycles.
Prospective randomized controlled trial.
Materials and Methods:
A total of 77 patients, less than 40 years of age, who had a history of at least two unsuccessful embryo transfers and received blastocyst transfer during hormone replacement treatment between February and June 2013, were enrolled in this study.
The patients were allocated into two groups according to the last digit of their clinical record number: an experimental group (n=22) that excluded patients who disagreed or couldn’t undergo in the appropriate period, and a control group (n=55).
In the experimental group, the endometrial scratch was performed once with an Endocyte® endometrial sampler during the luteal phase of the cycle preceding the embryo transfer.
The primary outcome measure was the clinical pregnancy rate. The secondary outcome measure was the ongoing pregnancy rate.
All the patients in case the intervention group provided written informed consent. The study procedures were approved by the Institutional Review Board of the Hanabusa Women’s Clinic.
No significant differences were found between the groups in terms of age or previous number of failed embryo transfers. The clinical pregnancy rate in the experimental group was 45.5%, while that of the control group was 21.8 %( p<0.05). The ongoing pregnancy rate was 100% in the experimental group, while that in the control group was 50.0%(p<0.05).
To the best of our knowledge, this is the first report on the effect of endometrial local injury (endometrial scratch) on frozen-thawed blastocyst transfer in hormone replacement cycles.
In this study, the clinical and ongoing pregnancy rates in the experimental group were significantly higher than in the control group.
In recent studies, the mechanical manipulation of the endometrium in the cycle preceding ovarian stimulation for in vitro fertilization and embryo transfer was shown to improve implantation rates in patients with unexplained recurrent implantation failure. We consider that, even for frozen-thawed embryo transfer, endometrial injury may increase pregnancy rates, and decrease the risk of miscarriage in patients less than 40 years of age with a history of at least two unsuccessful embryo transfers.