So what exactly is Pre-implantation Genetic Diagnosis?

Pre-implantation Genetic Diagnosis {PDG} is a screening test created through vitro fertilization {IVF} to identify genetic defects in embryos created during the IVF process, prior to transfer. In addition, PDG can be used to determine the gender of your child. PDG is, however, very expensive since its a more complex process compared to other IVF treatments.

How is PDG Performed?

An IVF is requred to retrieve fertilized eggs {embryos} for PGD. An assisted hatching on the embryos is done in the lab by an embryologist who will later transfer them to a uterus. Once embryos reach the blastocyst stage, the cells on the outside of the embryo are biopsied and sent for analysis.

It is during this screening, that a desired parent can see each embryo’s sex chromosome and transfer the embryos of the desired gender. From this, the gender of a baby is accurately determined.

Candidates for PGD

To qualify as a good candidate for a Pre-implantation Diagnosis Test, you need to be over 37 years of age, and have a history of recurrent miscarriages due to chromosomal abnormalities. Couples at risk of having a child affected with inherited genetic disease also qualify.

However, if the intended parents do not carry any known genetic diseases the can opt for Pre-implantation Genetic Screening {PGS}, a procedure that checks for abnormal number of chromosomes in embryos prior to transfer in IVF. PGS and PGD use similar processes to analyze embryos.

Pros and Cons of PDG

Pros of PDG

  1. Wide spectrum of detection- Risks associated with genetic issues such as Sickle-cell Anemia, Hemophilia, Rett Syndrome, and Cystic Fibrosis can easily be detected through PDG.
  2. Earlier detection- Your physician can choose embryos that will increase chances of conceiving a healthier child and freeze those with any chromosomal abnormalities.
  3. Prevents genetic transmission of unknown abnormalities- PDG is the best option if one or both intended parents have known genetic disorders such as Cystic Fibrosis. As a physician selects the embryos viable for selection, they are able to rule out those that are chromosomally abnormal and would prevent healthy birth.

Cons of PDG

  1. Possibility of embryo destruction- Studies show that there is about 20% chances an embryo can be damaged by the biopsy process required for PDG, causing the embryo to stop growing. A damaged embryo results to a viable pregnancy.
  2. Chances of undetected disease– PDG, like any other form of testing, is subject to inaccuracy, and some genetic traits may be missed during the procedure.

Final Thoughts

The existence of PDG is one reason for couples with high risk pregnancies to be hopeful. PDG, however, can be time consuming, invasive and very expensive. Ask your doctor to help you understand how PDG and IVF works and its potential risks.