Texas Fertility Center San Antonio

Preimplantation Genetic Testing, or PGT

Preimplantation genetic testing increases the odds of IVF success

Hopeful parents who want the best chance of bringing home a healthy baby should ask the team at our San Antonio IVF clinic about preimplantation genetic testing, or PGT. There are two types of genetic testing that laboratory professionals can perform on embryos before transfer to a hopeful mother’s uterus.

A look at the two types of preimplantation genetic testing

Our San Antonio IVF clinic offers both preimplantation genetic screening (PGS) and preimplantation genetic diagnosis (PGD). PGS screens for chromosomal abnormalities (i.e. abnormalities in the number of chromosomes that are present in an embryo), while PGD can detect the presence of specific genetic disorders. Both forms of preimplantation genetic testing are extremely accurate and can help ensure IVF success and a healthy baby.

The process of preimplantation genetic testing

Both forms of preimplantation genetic testing occur during an IVF cycle, between the steps of fertilization and embryo transfer. An embryo reaches the blastocyst stage on Day 5 to 7 of development. At that time, the embryologists at our San Antonio IVF laboratory will use a microscopic laser to make a tiny hole in the outer membrane that surrounds the blastocyst. They will then carefully remove three to five of the approximately 128 cells that make up the blastocyst. This is known as a trophectoderm biopsy, and it does not typically harm the embryo.

If patients want PGS or PGD to be part of their IVF cycle, our embryologists will freeze the biopsied cells and send them by courier to one of several national genetic testing laboratories. Five to seven business days later, our San Antonio IVF clinic will receive the results that tell us which embryos are healthy. Our fertility specialists will use this information to transfer a euploid, or normal, embryo that has the correct number of chromosomes, and if PGD was performed, is free of a specific genetic disease.

If hopeful parents select PGS, the genetic specialists at the outside testing laboratory will look at the chromosomal makeup of the biopsied cells from each embryo to ensure that it has 46 chromosomes. By transferring embryos with the normal number of chromosomes, our San Antonio IVF clinic has generated ongoing pregnancy rates of 60% to 70% per embryo transferred. PGD, on the other hand, evaluates the embryo to determine whether it carries a specific genetic disorder – such as sickle cell, Tay Sachs, spinal muscular atrophy, for example. There are over 300 known genetic disorders that can be detected.

Don’t forget about preconception carrier screening

Many hopeful parents don’t realize that they could be a carrier of a genetic disorder that they could pass to their future children. Many of these symptomless carriers only discover their carrier status after giving birth to a child with a devastating illness such as cystic fibrosis, sickle cell disease or spinal muscular atrophy.

To avoid this heartache, our San Antonio IVF clinic team recommends that both parents undergo preconception carrier screening before attempting pregnancy. If one or both parents carry the disorder, preimplantation genetic testing can prevent the transmission of the disease.

Contact us to schedule a consultation with our San Antonio IVF clinic. We are happy to discuss preconception carrier screening and preimplantation genetic testing with you.