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Mosaic Embryos

We’ve got the answers to your questions about mosaic embryos

When you start to dive into the world of in vitro fertilization (IVF), you’re introduced to new terms and concepts. We don’t expect you to find the answers yourself, which is why our Austin fertility doctors are here to guide you. Patients often want to know whether their IVF embryos are chromosomally normal or abnormal. Preimplantation genetic testing for aneuploidy (PGT-A) can shed some light on this topic. However, it can also raise other questions when there are mosaic embryos.

What are the different types of IVF embryos?

When patients have IVF, they can also order PGT-A for their embryos. This form of testing allows embryologists to determine whether an embryo is chromosomally normal (euploid) or abnormal (aneuploid).

In the past, PGT-A was only precise enough to determine whether an embryo was normal or abnormal. However, reproductive medicine and testing has come a long way, so we now know that there can be a middle ground in the form of mosaic embryos.

These embryos contain both normal and abnormal cells, and we know that about 20% of all embryos are mosaic. However, this number increases with maternal age because egg quality and quantity decline over time.

Can mosaic embryos develop into healthy babies?

Just because an embryo has a mix of normal and abnormal cells, 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 only in 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 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 healthy baby?

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 doctors realize this is a deeply personal decision, so they will provide compassionate support and guidance to help patients make this choice.

If you still have questions about IVF embryos, contact us to schedule an appointment. We can help you learn more so that you can have peace of mind as you build your family.