Introduction. 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 both 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 of the quality of embryos.
Assessment of Embryo Quality. Embryos can be 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 metabolomes.
A more detailed monitoring of the kinetics of the embryo development can be
related 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 preimplantation genetic
screening is used to enhance the success rate of the assisted reproduction
cycles. Conclusion. 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.
Preimplantation genetic screening will play a dominant role in selecting embryos for single embryo transfer
