The process of Preimplantation Genetic Testing (PGT) is a meticulous journey that begins after embryos are created through in vitro fertilization (IVF). It's a sophisticated procedure designed to analyze the genetic makeup of these early-stage embryos before they are transferred to the uterus.

The first critical step is the embryo biopsy. This is typically performed when the embryo has reached the blastocyst stage, usually on day 5, 6, or 7 of its development. At this point, the embryo has differentiated into two main cell types: the inner cell mass (which will form the fetus) and the trophectoderm (which will form the placenta). A highly skilled embryologist carefully removes a small number of cells (typically 5-10) from the trophectoderm using a laser and a micro-pipette. This biopsy is considered safe for the embryo, as these cells are destined to become part of the placenta and not the baby itself.

Once the cells are biopsied, they are then sent to a specialized genetics laboratory for genetic analysis. The embryos, meanwhile, are typically cryopreserved (frozen) while awaiting the test results. In the lab, the DNA from the biopsied cells is amplified and then analyzed using various advanced genetic techniques, depending on the type of PGT being performed (e.g., PGT-A, PGT-M, PGT-SR). This analysis identifies chromosomal abnormalities or specific genetic mutations.

Finally, based on the comprehensive genetic report, the fertility team can then select the chromosomally normal and/or mutation-free embryos for embryo transfer. This ensures that only the healthiest embryos with the highest potential for a successful pregnancy are chosen, significantly increasing the chances of a healthy live birth.