All three types of PGT are performed in a similar way. The patient goes through their IVF cycle and egg retrieval as recommended by their physician. Their embryo(s) are monitored in our laboratory until day 5 or 6 when they are referred to as blastocysts. At that time, a small number of cells are biopsied (removed) from each embryo and shipped to an outside laboratory for PGT. The cells are taken from a part of the blastocyst called the trophectoderm, which will eventually form the placenta. These cells are expected to be representative of the rest of the embryo; however, this may not always be the case due to circumstances such as mosaicism (see question 13). The embryo(s) must be frozen while PGT is performed. An embryo with normal PGT results would be selected, thawed, and transferred to the uterus of the patient or their gestational carrier at a later date.

There are several potential benefits of PGT-A. For patients with several good quality embryos, PGT-A is an additional tool that may assist in the selection of the best embryo for transfer. For patients whose embryos have PGT-A, we recommend the transfer of a single chromosomally normal embryo which reduces the chance of multiples (e.g. twins or triplets) and increased risk of complications associated with those types of pregnancy. PGT-A may also be helpful when a patient has excess embryos they plan to store for future attempts at pregnancy. Since embryos with aneuploidy are more likely to result in a failed transfer or miscarriage, PGT-A results provides additional information about the reproductive potential of those stored embryos and a more complete picture of what a patient has available for the future. Normal PGT-A results also reduce the likelihood of the birth of a child with certain detectable chromosome condition like Down syndrome, trisomy 13, or trisomy 18. Study outcomes have been mixed when considering whether PGT-A helps to reduce a patient’s miscarriage risk and increase their likelihood of a live birth and may depend on the characteristics of the individual patient (such as their age). If you are interested in learning more about PGT-A, we recommend you discuss this test with your physician and our genetic counselor. We can review your individual circumstances to help you determine if PGT-A is right for you.