Once embryos are created through in vitro fertilization (IVF), Shady Grove Fertility offers two different types of preimplantation testing that can look for chromosomal abnormalities or specific diseases within the embryos.
Preimplantation Genetic Diagnosis (PGD)
Your physician may recommend genetic testing of embryos—known as preimplantation genetic diagnosis (PGD)—if you and your partner are known carriers for genetic disorders such as cystic fibrosis, fragile X syndrome, or myotonic muscular dystrophy. We also recommend PGD for patients with infertility related to chromosomal abnormalities such as recurrent pregnancy loss or repeated unsuccessful IVF cycles.
PGD: What to Expect
Once fertilization occurs and embryos develop over the next 5 to 6 days to the blastocyst stage, an embryologist will biopsy a group of cells from each embryo. The biopsied cells are analyzed in a genetic testing laboratory to determine if they are affected with the genetic disorder that you are known to carry. The blastocysts undergo cryopreservation until the results of the analysis are available. An embryologist can then thaw the embryos that are normal—not affected by the genetic disorder they were screened for—and the physician can transfer one or more to the uterus in a subsequent frozen embryo transfer (FET) cycle.
Preimplantation Genetic Screening (PGS)
In addition to testing for genetic mutations (PGD), embryo freezing has allowed for preimplantation genetic screening (PGS). PGS looks for abnormalities in chromosome number, such as trisomy 21, which causes Down syndrome, and many others that are likely to result in implantation failure or miscarriage.