Conclusions
The main discovery of this study is to distinguish into two types of implantation failure patients, the ones that could be benefited by PGT-A and the ones that are not benefited due to the implantation failure origin. There is no clinical evidence that ERA test benefits any patient, pET cannot be based on the morphological characteristics of the embryo and chromosomal screening should be considered for M-RIF patients. Additionally, ERA cannot identify the most appropriate time for embryo transfer and cannot detect uterine diseases making the endometrium unsuitable for implantation. New technologies may be necessary to assess the endometrial aspect of implantation. A more thorough investigation of the effect of pET on reproductive outcomes could also shed light on the role of the endometrium. Prospective studies with enough power are needed to evaluate whether ERA has a clinical benefit. Although S-RIF was uncommon in our population of IVF patients, it warrants further study because designing treatments for this condition will likely prove challenging.