PGD or preimplantation genetic diagnosis is a process done for IVF patients. IVF with PGD or also known as embryo screening is a technique used to screen potential embryos that carry genetic disorder or it can also be a treatment for patients with recurrent miscarriages. This technique involves removing a single cell from an embryo and examining it if it carries a disease or disorder. Screening can also be done to detect any chromosomal disorder which causes miscarriages.
PGD is used for a number of reasons:
- To check for any inherited genetic disease that may have passed onto the eggs.
- To check for embryos with abnormal chromosomes.
- To check for the best embryos or embryos with high potential of implanting in the uterus.
- To check for the embryo's sex.
Who can use PGD?
PGD has become more popular these days but not all women are qualified to use PGD. Strict guidelines are implemented and only a few are allowed to use IVF with PGD, they are:
- Couples with family history of genetic disorders
- When either one of the couples is a carrier of a chromosomal translocation
- Women who experience recurring miscarriages
- For women ages 38 and above
- For couples who have at least 3 repeated failed IVF
- For couples who have low sperm count where ICSI is necessary
How is PGD done?
IVF with PGD is done after retrieval of the eggs and before returning them back to the uterus. When a fertilized egg has developed into 4 to 10 cells or around day 3 after fertilization, a hole is made into the embryo's shell. Using a pipette, one cell is gently removed for testing. This technique is called blastomere biopsy.
A DNA will be removed from the cell to check for any potential genetic disorder or for any chromosomal abnormality. Any abnormal embryos will be destroyed.
All the testing would be completed in one day and the screened healthy embryos will be ready to be implanted the next day. For some cases like blastocyst transfer, the embryos will be stored for a few more days until the embryos reached its blastocyst stage.
Ethical Issues concerning PGD
There have been many controversial ethical issues associated with PGD. Many find it unethical to create and destroy an embryo outside a woman's body. IVF with PGD is not 100% effective and it does not guarantee that a screened embryo will be born without a disorder. However, some think that PGD has its positive points especially since it helps correct problems with miscarriages and genetic disorder.
PGD can also help you choose the sex of the baby and this may be a big factor when you want to balance your family. But some contend that selecting a gender might lead to social preferences mostly for male sex. This may in turn lead to a bigger society problem.
When a family member or a relative is in need of stem cell transplant, PGD can offer big hope for these families. Through PGD, it's easy to identify embryos with a perfect match for the ailing member. Once born, stem cells in the umbilical cord would be used for transplant, giving no harm neither to the baby nor the mother.
There has been no strong evidence that IVF with PGD increases struggling couple's chances of conceiving. PGD has its own ups and down. So before going through IVF know your options, understand the procedure and don't be afraid to take chances.