Analysis of factors influencing morphokinetic characteristics of embryos in ART cycles.

In this article, some factors were evaluated for their impact on embryo morphokinetics during assisted reproductive technology (ART) cycles. We detected significant differences in the fourth cell division time (t5) of embryos obtained after controlled ovarian stimulation in long GnRH agonists and GnRH antagonist protocols. We also found that higher gonadotropin dose may slow down the development of embryos. However, both male and female age, the number of oocytes and number of normal forms of sperm in the ejaculate did not affect the kinetic parameters of embryo development. Further research is needed to identify all the spectrum of factors, which can affect the rate of embryo development.