Embryo Mosaicism

Technology has come a long way in the last several years. It’s hard to believe that smart phones only just became popular this decade! Big technological leaps have also been made in the world of IVF and Assisted Reproductive Technology (ART). For example, it is common practice for reproductive endocrinologists to advise couples to test their embryos to make sure they are genetically “sound.”

According to the American Pregnancy Association, pre-implantation genetic diagnosis (PGD) is a procedure used prior to implantation to help identify genetic defects within embryos created through IVF. This serves to prevent families from giving birth to children who will exhibit certain genetic disorders. Fertility doctors will usually recommend these tests to families who are carriers of certain diseases, chromosomal disorders, and women who are over the age of 35 or who have experienced recurrent pregnancy loss.

However, it is important to note that PGD is not an accurate indicator of an embryo’s risk of producing a child with genetic abnormalities. In fact, most embryo adoption agencies in the U.S. have a policy against families testing their embryos for genetic conditions due to this reason. It is still possible to give birth to completely healthy baby even if the embryo tested “abnormal.”

How can this be? A research study that came out in 2016 indicated that some (if not most) embryos created via IVF are mosaic embryos. In other words, the embryos contain normal and abnormal cells. And this is more common than you might think! Embryos do have the ability to correct abnormal cells as they grow and develop. If only the abnormal cells are tested, then the whole embryo could be labeled abnormal, even though it could grow into a perfectly healthy baby. This video features Dr. Norbert Gleicher, MD, who performed this research study, explaining mosaicism and how they can skew test results.

What should we take away from this? If anything, families who are pursuing embryo adoption should keep in mind that adopting PGD-tested embryos is not the end-all-be-all of pregnancy success. There are many families who adopt PGD-tested embryos, only to have none of those embryos result in a baby. Even if your adoption agency does not allow adopting families to test the embryos, you are still given an extensive medical background on the placing family and the children born from the embryos. Many times, you are even allowed to see pictures of the family! And if you’re pursuing an open adoption, you will always have up-to-date knowledge on the placing family’s medical history.

To learn more about embryo donation and adoption, visit EmbryoAdoption.org