Received December 05, 2019
Accepted July 02, 2020

Objective: The primary objective was to find out the endometrial predictors of clinical pregnancy in a population of repeated implantation failure in oocyte donation after specific endometrial treatment. The secondary one was to evaluate the reproductive results in terms of Implantation rate (IR), Clinical pregnancy (CP), Live birth delivery rate (LBDR) and Prematurity in relation to normalization or no-normalization of the predictors. Method of study A total of 66 patients were assigned to the study. A Pippelle endometrial biopsy was taken to investigate the endometrium lymphocyte population by Flow Citometry and abnormal/normal patterns by histopathology, in pre/post-treatment. The binary logistic regression model was applied to identify the predictors for CP. For the secondary objective, the clinical results were evaluated in function to the normalization or no normalization in post-treatment. Results Endometrial histopathology and endometrial NK cell counts resulted in CP predictors (Wald chi2 test (p = 0.044 and 0.001)) respectively. A higher IR, CP and LBDR was obtained when both predictors were normalized in comparison with no normalized (p<0,001). A high percentage of prematurity was observed in both normalized vs. non-normalized groups (34.4% (11/32) and 71.43% (5/7) respectively) without significant difference. Conclusion The endometrial histopathology and the endometrial NK cell counts showed that they are valid predictors of pregnancy outcome in repeated implantation failure after treatment. In post-treatment, the pregnancy outcomes were significantly higher in the presence of both normalized predictors. In the no-normalization of the both predictors the pregnancy rate was zero. A high percentage of prematurity was observed in both groups.