Fertility Blog

Preimplantation Genetic Testing and Why Your Doctor Recommends It

By Simone Yap, ELD, Senior Embryologist at Washington Fertility Center

Your fertility specialist may have recommended this testing for your upcoming in vitro fertilization (IVF) cycle and you’re not sure why or what the testing is all about. In general, preimplantation genetic testing (PGT) refers to testing the DNA of an embryo for abnormalities before it is put back into the uterus. By transferring only normal embryos from an IVF cycle, this screening helps to:

  • Reduce the likelihood of miscarriages
  • Reduce the risk of an abnormal pregnancy
  • Reduce the time and cost to achieve a healthy baby (fewer repeat IVF cycles)
  • Increase the likelihood of single embryo transfers

There are two types of genetic testing:
• PGD: preimplantation genetic diagnosis tests embryos for a specific, known genetic disorder (e.g. Muscular Dystrophy, Cystic Fibrosis).
• PGS: preimplantation genetic screening tests embryos for chromosomal abnormalities - too many or too few chromosomes, known as “aneuploidy” (e.g. Down Syndrome) - missing, extra or rearranged DNA.

Who should undergo testing?
According to the American Society for Reproductive Medicine, PGD is recommended for someone who has or is a carrier of a known genetic disorder. PGS may be recommended for someone with recurrent miscarriage, someone who is older or whose ovaries do not work as well as expected, or someone with multiple failed fertility treatments.

How is testing performed?
This is done in the fertility center’s laboratory during an IVF cycle by taking a few cells from each embryo (biopsy) and sending them to a genetic testing lab. The cells and embryos are then frozen after the biopsy to allow for the time needed to complete the genetic testing. Any normal embryos can then be transferred in subsequent frozen embryo transfer cycles (FET) improving the chance to achieve a healthy pregnancy.

For more information about preimplantation genetic testing at Washington Fertility Center, please contact our office today.