PGS & PGD at Fertility Institute of Texas
During the process of IVF, it is possible to do testing on the embryos, which may increase the rate of pregnancy, decrease the risk of miscarriage and increase the chances of having a healthy baby. With preimplantation genetic screening, or PGS, the embryos are allowed to grow out to the day 5 or 6 stage. The embryos that develop into an expanded blastocyst (an advanced stage embryo) clearly have 2 unique types of cells—those that will become the baby and those that will become the placenta.
Testing for genetic abnormalities
The embryologist then creates a small hole in the shell of the embryo and takes a sample of the cells that are going to become the placenta. The embryo is then cryopreserved and the cells are sent to a lab where they undergo testing to reveal which embryos have a normal karyotype (normal number of chromosomes) and which ones do not. This is important because chromosomal abnormalities are the main reason that embryos do not implant in the uterus and are the main cause of miscarriage. There are many types of chromosomal abnormalities, but some of the most commonly known abnormalities are Down’s syndrome (trisomy 21) and Turner’s syndrome (monosomy X).
About preimplantation genetic diagnosis – PGD
Some women and men may have genetic abnormalities called single gene defects that they do not wish to pass on to their children, such as cystic fibrosis, sickle cell disease, and spinal muscular atrophy -SMA-, to name a few. Through a similar process as explained above, we can tell which embryos would and would not result in an affected child with the specific disease, allowing us to select an embryo that would result in a child without the disease in question. This process is called preimplantation genetic diagnosis, or PGD.
If you are considering fertility treatment and have concerns about genetic abnormalities, board certified reproductive endocrinologist Dr. Susan Hudson can discuss these treatments with you in detail. Call Fertility Institute of Texas today for a consultation.
New Braunfels 830.608.8004