Aneuploidy is a condition in which embryos do not have the normal number of chromosomes. Normally, humans have 46 chromosomes, which means 23 pairs of chromosomes, with 1 pair being XX or XY depending on the gender of the embryo. In cases of aneuploidy, embryos may have extra or fewer chromosomes due to abnormalities in the gametes or early stages of embryo development.
An euploid embryo is an embryo that has the correct number of chromosomes while an aneuploid embryo on the contrary has an incorrect number of chromosomes – this means that there is one chromosome more or one chromosome less, for example, and in this case, these embryos that are considered aneuploid they cannot be transferred because can lead to pregnancy loss.
Aneuploidy is the presence of an abnormal number of chromosomes. One or more chromosomes can be duplicated or missing in those embryos. Aneuploid embryos can lead to increased rates of miscarriages, birth defects and IVF failure. Studies confirm that the risk of aneuploid embryos increases with maternal age. Preimplantation genetic testing for aneuploidy (PGT-A) studies the number of chromosomes in embryos. It can be useful in special cases, such as an advanced maternal age. Examples of aneuploid embryos include trisomy 18 and trisomy 21, also known as Edward and Down sindrome.
