What Are The Factors Acting On the Embryonic Development?

One of the most important factors that determine the success of assisted reproduction treatment is the growth of the embryo. After the sperm and egg are brought together under in vitro conditions and after the egg is fertilized, the embryo development is monitored daily and sometimes hourly. A device called an embryoscope allows us to observe the embryo for 24 hours and follow its development closely. Slowing of embryonic development is an untoward finding. A rapid embryonic development is an unfavorable finding, too. While the quality of the embryo is predominantly determined by the quality of the egg, the quality of the laboratory and the experience of the embryologists are the other factors that act on the development of the embryo. If the embryo quality is not favorable, it may be considered to change the medication regimen in the next treatment and to schedule the transfer earlier. For the embryonic development, especially day 5 indicating the blastocyst stage is critical. In patients with more than one egg, embryos are definitely required to reach this stage. It is known that the blastocyst transfer results in high chances of pregnancy in eligible patients.

Many different scoring systems are developed to estimate embryonic development but each laboratory has to define its own development criteria. In particular; the cell number, symmetry, division rate, and the presence of a variety of intracellular structures determine the quality of the embryo. Culture environment, temperature, atmosphere suitable for the embryo, and light are the factors that affect the development of the embryo.  In addition to evaluating the development of the embryo, the ""normality"" of the chromosome structure can be examined by genetic tests. This procedure is called ""preimplantation genetic diagnosis"". A good quality development means a high chance for the establishment of the pregnancy. Changes in the laboratory environment affect the development of the embryo; therefore, continuous monitoring of environmental indicators is critical for quality control procedures. The candidate mother should be informed about the embryonic development before the embryo transfer.