Mitochondria are organelles that provide energy for the embryo and also have many functions for cells. Eggs and embryos contain hundreds of mitochondria, each carrying its own DNA.
Mitochondrial DNA contains very important information about the metabolism and energy production of the cell and has an important role in the development and quality of the embryo. The weak repair mechanism of mitochondrial DNA and the fact that it is easily affected by aging and other factors directly affect embryo development and pregnancy success. One important result pointed out by the studies on this subject is “ Increases in the amount of mitochondrial DNA belonging to the embryo adversely affect pregnancy success and live baby birth. On the other hand, it has been demonstrated that changes in the mitochondrial DNA of embryos are also associated with increased chromosomal aberrations of the embryo. Studies have revealed the relationships between embryo quality and pregnancy success and mitochondrial DNA within the framework of the following results:
As the amount of mitochondrial DNA increases, it negatively affects the potential for implantation (the embryo attaches to the mother’s uterus), so choosing embryos that have not increased the amount of mitochondrial DNA increases pregnancy success.
The amount of mitochondrial DNA in embryos of older women was found to be higher than in embryos of young mothers. Therefore, the negative effects of advanced maternal age (mitochondrial stress) cause an increase in the amount of mitochondrial DNA of embryos.
Again, studies have shown that the amount of mitochondrial DNA was found to be high in embryos with chromosomal disorders (aneuploid).
It has been shown that in cases where mitochondrial DNA exceeds a certain threshold value, the rate of continuation of pregnancy decreases relatively and pregnancies result in early miscarriage. ( A Diez Juan, F&S, 2015, Elpida Fragouli,PLOS Genetics, 2015)
Based on all these results, mitochondrial DNA measurement in embryos during IVF applications emerges as an important criterion in embryo selection.
Embryo analyzes with the NGS (New Generation Sequencing) method allow us to check the chromosomal status of the embryo on the one hand, and also enable us to measure the amount of mitochondrial DNA on the other. Mitochondrial DNA quantity measurement, which is thought to make an important contribution to the increase in IVF success, is applied in our laboratory using the “NGS method” and “Real Time PCR” method.
Thanks to the NGS method, we can test both the chromosomal status and the amount of mitochondria of each embryo simultaneously, so we can reach the result in a short time and reliably within the same analysis platform.
Biopsy (3rd or 5th day biopsies) material to be performed for chromosome analysis (aneuploidy screening) from the embryo is used simultaneously in this test, so there is no need for a second intervention for the embryo. The application of the method in our own laboratory provides advantages such as reaching the result in a shorter time compared to other similar tests performed abroad (MitoScore) and excluding the negativities that may arise from transportation.
prof. Dr. Volkan Baltaci