Preimplantation Genetic Diagnosis (PGD): Benefits and Concerns
Preimplantation genetic diagnosis (PGD) is a procedure used to help identify genetic defects within embryos created by in vitro fertilization to prevent certain diseases or disorders from being passed on to the child.
How is the DGP performed?
Preimplantation genetic diagnosis (PGD) begins with the standard in vitro fertilization (IVF) procedure, which includes egg retrieval and fertilization in a laboratory. Over the next three days, the embryo will divide into eight cells.
PGD involves the following steps:
- First, one or two cells are extracted from the embryo.
- The cells are being evaluated to determine if the inheritance of a problematic gene is present in the embryo.
- Once the PGD procedure has been performed and embryos free of genetic problems have been identified, the embryo is placed back into the uterus, and implantation will be attempted.
- Any additional embryos that are free of genetic problems can be frozen for future use, while embryos with the problematic gene are destroyed.
Who can benefit from DGP?
Preimplantation genetic diagnosis (PGD) can benefit a couple at risk of passing on a genetic disease or condition.
The following is a list of the types of people who are potential candidates for PGD:
- Carriers of sex-linked genetic disorders
- Carriers of single-gene disorders
- People with chromosomal disorders
- Women aged 35 and over
- Women who experience recurrent pregnancy loss
- Women with more than one failed fertility treatment
PGD has been used for the purpose of sex selection. However, discarding embryos based solely on sex considerations is an ethical concern for many people.
What are the benefits of PGD?
The following are considered the benefits of DGP:
- PGD can test for more than 100 different genetic conditions.
- The procedure is performed before implantation, thus allowing the couple to decide whether they wish to continue with the pregnancy.
- The procedure allows couples to continue having biological children they would not have been able to do otherwise.
What are the DGP’s issues?
The following are considered issues or disadvantages associated with the use of DGP:
- Many people believe that because life begins at conception, the destruction of an embryo is the destruction of a person.
- While PGD helps reduce the likelihood of conceiving a child with a genetic disorder, it cannot completely eliminate this risk.
- In some cases, additional testing during pregnancy is needed to determine if a genetic factor is still possible.
- Although genetically present, some diseases only produce symptoms when carriers reach middle age. The likelihood of developing a disorder should be discussed with a healthcare professional.
- Please note that preimplantation genetic diagnosis does not replace the recommendation for prenatal testing.
If you are interested in PGD, talk to your doctor, a genetics specialist, or a fertility specialist to discuss your options.
Compiled using information from the following sources:
American Society for Reproductive Medicine. (2014). Preimplantation genetic testing. Retrieved from https://www.asrm.org/uploadedFiles/ASRM_Content/Resources/Patient_Resources/Fact_Sheets_and_Info_Booklets/PGT_2014.pdf
Chromosome Screening. (n.d.). Single gene PDG: Helping carriers of single gene disorders have a successful pregnancy and a healthy baby. Retrieved from https://www.chromosome-screening.org/single-gene-pgd
Human Fertilization Embryology Authority. (2014). Pre-implantation genetic diagnosis (PGD).
Penn Medicine. (n.d.) Preimplantation genetic diagnosis (embryo screening). Retrieved from https://www.pennmedicine.org/fertility/patient/clinical-services/pgd-preimplantation-genetic-diagnosis/
