Preimplantation genetic diagnosis is commonly used in the in vitro fertilization procedure, just before the embryo is introduced in the uterus of the mother. The preimplantation genetic diagnosis can establish whether the embryo is healthy and ensure that there are no risks of spontaneous abortion during the pregnancy.
When Is PGD Indicated
A PGD is indicated in a number of instances such as:
- When the mother is advanced in age (over 40), because after this age the babies are more likely to be affected by genetic diseases, given the fact that the healthiest eggs are released during youth
- If any of the parents have a genetic disease or have a relative with a genetic disease
- If the parents have chromosome translocations, which may affect the implantation or result in abortion
- If any of the parents carry autosomal recessive or dominant diseases
Even healthy couples that go through IVF can opt for PGD. Embryos that are found to have a defect are not transferred into the mother's uterus, as the pregnancy may not be viable and the baby is very likely to be born with a genetic defect.
Types of PGD
There are three main types of PGD available today:
- The FISH method (fluorescence in situ hybridization)
- The PCR (polymerase chain reaction)
- Haplotyping, which is the latest procedure discovered
New procedures may be researched in the future and be used to detect even more conditions that may affect the baby.
The Future of PGD
Preimplantation genetic diagnosis is a new procedure and will surely have a long future ahead of it with improvements made to the already existing techniques. PGD has been the object of study of fertility researchers for several years, but the first preimplantation genetic diagnosis with successful results was registered in 1988.
The procedures have been improved, but they still have some shortcomings, the main objection being that a few cell samples may not carry enough information on the embryo and many viable embryos may be discarded. Additional testing and research is needed in all the PGD techniques, to ensure their accuracy and effectiveness in IVF. Fertility researchers are dealing with the PGD techniques and may come up with more advanced technologies as time goes on.
PGD is used in a low number of clinics, so in the future, more and more fertility clinics may adopt these techniques. Presently, only specialists that are familiar with cell micromanipulation can perform PGD; in the future, fertility specialists may attend more training sessions to learn the PGD techniques.
Specialists hope that in the future the PGD will enable them to find genetic information that will eventually cure diseases such as diabetes, cancer or heart disease.