Texas Fertility Center

Mosaic Embryos

Texas Fertility Center answers questions about mosaic embryos

Patients sometimes ask our Austin fertility doctors questions about mosaic embryos. As the world of reproductive medicine changes, we gain new insights into embryos and development. In the past, fertility specialists thought that embryos could only be chromosomally normal or abnormal. Mosaic embryos prove that there is a middle ground.

What are mosaic embryos?

When patients undergo in vitro fertilization (IVF) with our Austin fertility doctors, they can opt to include preimplantation genetic testing (PGT) on their embryos. This form of testing allows embryologists to determine whether an embryo is chromosomally normal (euploid) or abnormal (aneuploid).

In the past, PGT was only precise enough to determine whether an embryo was normal or abnormal. Now, it can determine whether an embryo contains both normal and abnormal cells. This is known as a mosaic embryo.

About 20% of embryos are mosaic. This number increases with maternal age because egg quality and quantity decline with age.

Can mosaic embryos develop into healthy babies?

Just because an embryo is mosaic, it doesn’t mean that it can’t mature into a healthy baby. When an embryo divides rapidly after fertilization, mistakes can happen during cell division. A healthy baby can develop if those abnormal cells die off and the embryo self-corrects. This can also occur if the abnormal cells are limited to what will become the placenta.

However, if the abnormal cells multiply in the embryo, there could be problems. For example, it could result in implantation failure, miscarriage or a baby with serious birth defects. This uncertainty leaves questions in many intended parents’ minds. Should they discard mosaic embryos to avoid potential issues, or should they transfer one in hopes that it will develop into a normal pregnancy?

Before deciding, we recommend speaking to our Austin fertility doctors and a genetic counselor. We will always transfer chromosomally normal embryos before mosaic ones. However, our team may consider transferring a mosaic embryo if the only remaining embryos are abnormal. Our Austin fertility doctors realize that this is a deeply personal decision and they will provide compassionate support and guidance as patients make this choice.

Contact us to learn more about mosaic embryos and preimplantation genetic testing at Texas Fertility Center.