Small Non-coding RNAs in Embryonic Pre-implantation.

Failure of embryo implantation has been introduced as an important limiting parameter in early assisted reproduction and pregnancy. The embryo-maternal interactions, endometrial receptivity, and detections of implantation consist of the embryo viability. For regulating the implantation, multiple molecules may be consistent; however, their specific regulatory mechanisms still stand unclear. MicroRNAs (miRNAs) have attracted a lot of attention due to their important effect on human embryo implantation. MicroRNA (miRNA), which acts as the transcriptional regulator of gene expression, is consisted of embryo implantation. Recent studies indicated that miRNAs not only act inside the cells but also can be secreted by cells into the extracellular environment via multiple packaging forms, facilitating intercellular communication and providing indicative information related to various conditions. The detection of extracellular miRNAs provided new information in cases of implantation studies. For embryo-maternal communication, MiRNAs offered novel approaches. In addition, in assisted reproduction, for embryo choice and prediction of endometrial receptivity, they can act as non-invasive biomarkers and can enhance the accuracy in the process of reducing the mechanical damage for the tissue.