Non-invasive evaluation of embryo quality for the selection of transferable embryos in human in vitro fertilization-embryo transfer

The ultimate goal of human assisted reproductive technology is to achieve a healthy pregnancy and birth, ideally from the selection and transfer of a single competent embryo. Recently, techniques for efficiently evaluating the state and quality of preimplantation embryos using time-lapse imaging systems have been applied. Artificial intelligence programs based on deep learning technology and big data analysis of time-lapse monitoring system during in vitro culture of preimplantation embryos have also been rapidly developed. In addition, several mo-lecular markers of the secretome have been successfully analyzed in spent embryo culture media, which could easily be obtained during in vitro embryo culture. It is also possible to analyze small amounts of cell-free nucleic acids, mitochondrial nucleic acids, miRNA, and long non-coding RNA derived from embryos using real-time polymerase chain reaction (PCR) or digital PCR, as well as next-generation sequenc-ing. Various efforts are being made to use non-invasive evaluation of embryo quality (NiEEQ) to select the embryo with the best develop-mental competence. However, each NiEEQ method has some limitations that should be evaluated case by case. Therefore, an integrated analysis strategy fusing several NiEEQ methods should be urgently developed and confirmed by proper clinical trials.

Automated summary

The ultimate goal of human assisted reproductive technology is to achieve a healthy pregnancy and birth by selecting and transferring competent embryos. Currently, techniques such as time-lapse imaging systems and deep learning technology have been used to evaluate the state and quality of embryos. In addition, analyzing molecular markers in spent embryo culture media and using non-invasive evaluation methods have shown promising results. However, further clinical trials are needed to confirm these methods.