Preimplantation Genetic Testing for Aneuploidy (PGT-A)
Many IVF cycles result in disappointment as the embryos fail to implant or the pregnancy ends in spontaneous miscarriage. We now know that many of the transferred embryos are genetically abnormal (chromosomally unbalanced). These genetically unbalanced embryos are generally not able to implant or develop into a healthy pregnancy and live birth. In some cases, however, pregnancies occur but later miscarry, or, in a small minority, result in abnormal pregnancy and live births. It is estimated that at least 50% of miscarriages are caused by genetically abnormal embryos in both natural and IVF pregnancies.
With advancing age, women in their late 30s and early 40s are at a significantly increased risk that their eggs will have more abnormalities. This leads to a correspondingly higher incidence of genetically unbalanced embryos following IVF.