Exploring Mosaic Embryos: What They Are and What They Mean for Fertility Treatments.
When an embryo is described as “mosaic,” it means that the embryo has a mix of normal and abnormal cells. In other words, some of the cells in the embryo have the correct number of chromosomes (euploid), while others have an abnormal number of chromosomes (aneuploid).
Mosaicism can occur during the process of cell division in the embryo, leading to some cells having an extra or missing chromosome. Mosaicism is relatively common, with studies suggesting that up to 20-30% of embryos may be mosaic.
The implications of mosaicism in embryos are still being studied, but research suggests that the pregnancy outcome for mosaic embryos is less predictable than for embryos with a normal chromosomal makeup. Some mosaic embryos may result in a healthy pregnancy and live birth, while others may result in miscarriage or other complications. The degree of mosaicism and the chromosomes involved can also affect the chances of a successful pregnancy.
As a result, decisions about whether to transfer a mosaic embryo are complex and need to be made on a case-by-case basis. In some cases, if there are no normal embryos available, a mosaic embryo may still be considered for transfer. However, in other cases, a mosaic embryo may not be transferred, and additional testing or embryo biopsy may be recommended to identify embryos with a normal chromosomal makeup.
Overall, while mosaicism in embryos is not uncommon, it is important to discuss the implications of mosaic embryos with your fertility specialist to determine the best course of action for your individual situation