What Influences Embryo Development?

One of the crucial factors determining the success of in vitro fertilization (IVF) treatment is embryo development. Sperm and egg are brought together in vitro, and after fertilization, embryo development is closely monitored on a daily, and sometimes hourly, basis. Slowing down of embryo development is an unfavorable sign, and conversely, rapid embryo development is not desirable. While egg quality predominantly determines embryo quality, the quality of the laboratory and the experience of embryologists are also factors influencing embryo development. If embryo quality is not optimal, considerations for the next treatment may involve changing medications or planning the transfer earlier. Particularly, the 5th day, known as the blastocyst stage, is crucial in embryo development. In patients with a high number of eggs, the development of embryos to this stage is always desired. It is well-known that blastocyst transfer in eligible patients offers a high chance of pregnancy.

Various scoring systems have been proposed for evaluating embryo development, but each laboratory must establish its own development criteria. Factors such as cell count, symmetry, division rate, and different formations within the cells play a role in determining quality. Environmental conditions such as culture medium, temperature, an atmosphere suitable for the embryo, and light also affect development. Besides evaluating the development of the embryo, genetic tests can be conducted to check whether the chromosomal structure is "normal"; this is referred to as preimplantation genetic diagnosis. Achieving high-quality development significantly increases the chances of a successful pregnancy.