ASSESSMENT OF THE EMBRYO QUALITY IN THE PROCEDURE OF IN VITRO FERTILIZATION

Since reproductive technologies are becoming increasingly popular among the couples with infertility problem, and having in mind that the success rate is still low, the clinicians tend to transfer more embryos in order to increase the probability of success. However; such a strategy increases the risk of multiple pregnancy, which brings about numerous risks to the health of boffi the mother and children. Therefore, an elective single-embryo transfer is set as imperative, which, on the other hand, would not be possible without selection and evaluation ofthe quality of embryos. Assessment of Embryo Quality. Embryos can he selected by various methods, from non-invasive to invasive methods. In non-invasive methods, the embryos are selected by their morphology or by the techniques based on the analysis of molecular components - analyses of the level of proteomes or metaholomes. A more detailed monitoring of th&kinetics of the embryo development can be re lated to the introduction of time-lapse imaging and monitoring systems into laboratory practice. The invasive methods encompass the techniques such as preimplantation genetic diagnosis and preimplantation genetic screening. In preimplantation genetic diagnosis, the assisted reproduction technologies cycle is approached for the genetic reasons, whereas preimplantatiori genetic screening is used to enhance the success rate of the assisted reproduction cycles.

In this paper we have shown that the application of elective single-embryo transfer requires the selection and assessment of the quality of embryos by the methods that have been developed in the last four decades, and still need further improvements.