The implantation rate of japanese infertile patients with repeated implantation failure can be improved by endometrial receptivity array (era) test: a randomized controlled trial

To investigate differences in implantation rate among Japanese patients with repeated implantation failure (RIF) undergoing transfer at the blastocyst stage in their first IVF/ICSI cycle randomized to deferred embryo transfer or personalized embryo transfer (pET) after endometrial receptivity array (ERA) test. Prospective randomized controlled trial that started in April 2016, with preliminary outcome evaluated in March 2018. Japanese patients with RIF were allocated through computer-generated randomization into deferred embryo transfer (DET) or pET groups. Sample size calculated for the endpoint of the implantation rate per embryo transfer was 253 patients per arm. We investigated the implantation rate of Japanese infertile women with RIF (mean age: 36.6 years old) in their first IVF/ICSI cycle with elective blastocyst transfer randomly allocated to DET group or pET group. The primary outcome in the present study was the implantation rate. Statistical analyses were conducted using univariate and multiple regression analyses. Significance was defined as p<0.05. All patients gave informed consent. The present study was approved by institutional review board. Our results have been analyzed after recruiting 506 patients of the 550 planned. The implantation rate was 8.7 % in the DET group and 19.0 % in the pET group. Therefore, pET is associated with significant improvement in the implantation rate versus regular DET (P=0004). Furthermore, multiple logistic regression analysis showed that pET (P=0.001) and blastocoele stage (P=0.025) were significantly associated with the implantation rate but that patient age (P=0.39), estradiol (E2: pg/m) value (P=0.77), progesterone (P4: ng/ml) value (P=0.64), trophectoderm grade (P=0.94) and inner cell mass grade (P=0.73) were not. The pET after ERA test and blastocoele stage are significantly correlated with the implantation rate for Japanese infertile women with RIF.