Time-lapse Microscopy in Preimplant Assessment of Human Embryos

Aim. Predicting the selection of euploid embryos based on morphokinetic assessment (KIDScore) of the development of preimplantation embryos using a time-lapse incubator. Design. A retrospective study. Materials and methods. 543 human embryos fertilized in vitro and cultured up to the fifth day of development in a time-lapse incubator using KIDScore were studied. Preimplantation genetic testing for aneuploidy (PGT-A) was performed using the Next Generation Sequencing method. Results. It was found that euploid embryos predominate among the embryos from the oocytes of women under the age of 36 years inclusive. In women 37 years of age and older, the number of aneuploid embryos exceeds the number of euploid ones. Age limits have been established for women (24–36 years old), when it may be reasonable to use the KIDScore assessment to select euploid embryos. Conclusion. Time-lapse microscopy does not provide an opportunity to identify methodological errors as a result of incorrect chromosome separation, which depends on the age of the mother and leads to an increase in the number of aneuploidies. For embryos from oocytes of women aged 24–36 years, with an increase in the KIDScore score, the chance of choosing a euploid embryo with the highest potential for development also increases. For embryos from oocytes of women 37 years of age and older, culturing in a time-lapse incubator with a KID Score only followed by PGT-A will increase the likelihood of choosing the most viable embryo. Keywords: assisted reproductive technologies, in vitro fertilization, morphokinetics, preimplantation genetic testing for aneuploidy, older, reproductive age.