Topics: Infertility, IVF, and PGD
Where is IHR located?
We have two facilities in the Chicago area. One is in Oakbrook, Illinois; the other is in the northeast area of Chicago. Find directions and contact on the locations page on this website.
Is it difficult to get to Chicago?
Chicago is in the middle of the U.S. and accessible from nearly anywhere in the world. The area is serviced by two major airports and there is an extensive rail system and public transportation network. When you contact us for an appointment we can provide detailed recommendations.
What is preimplantation genetic diagnosis?
By definition, preimplantation genetic diagnosis (PGD) is diagnosis of a genetic condition prior to achievement of a pregnancy. PGD was first performed in the early 1990’s as a way for couples to prevent the pregnancy of a child with genetic disease. Currently, we are able to perform PGD for many genetic conditions including single gene disorders and for chromosomal abnormalities.
What are chromosomes?
Chromosomes are the structures in our cells that carry our genetic information or genes. Our genes determine our physical makeup, growth and development. Normally, we have 46 chromosomes in each cell. Our children inherit 23 chromosomes from each parent, in the egg and sperm. A woman’s risk for having an abnormal number of chromosomes in her eggs increases with her age. Preimplantation genetic testing will detect the most common chromosomal abnormalities found during pregnancy. This includes Down syndrome, trisomy 13 and trisomy 18.
How can PGD help my family and me?
Preimplantation genetic testing is currently the only way to determine if the egg or embryo contains an abnormal number of chromosomes prior to pregnancy. This may not only contribute to the prevention of the birth of children with common chromosomal abnormalities, but also to the efficiency of IVF. PGD for chromosome problems can increase the chance of an embryo implanting, decrease the chance of miscarriage and decrease the likelihood of having a pregnancy with a chromosome problem (like Down syndrome). In essence, PGD can give your physician another way to determine which are the best embryos for transfer.
How is the testing performed?
There are two basic types of preimplantation diagnosis—polar body analysis and embryo analysis. Both types have their advantages and their limitations. Polar body testing focuses on the maternal contribution, and is an earlier method of testing which in some instances may have a higher accuracy. Embryo testing accounts for both maternal and paternal genetic contributions but occurs later and may not be as accurate.
What are polar bodies?
Polar bodies are the byproducts of the egg’s division. As an egg matures, it goes through a two-step division process, dividing once at the time when ovulation would occur and again at the time of fertilization. The two polar bodies are the products of this division which are essentially being discarded by the egg (oocyte). By analyzing the polar bodies, it is possible to infer the genetic status of the oocyte. Generally for aneuploidy, both polar bodies are removed following fertilization.
What is an embryo biopsy?
When an embryo becomes a 610 celled mass (approximately 3 days after egg retrieval), it becomes possible to directly test the embryo through removal of a single cell. Removal of this cell is usually not detrimental to the embryo, as all the cells are equivalent and no cell differentiation has occurred. The cell that is removed may then be analyzed to determine directly the genetic status of the embryo.
Does PGD replace prenatal testing?
No, PGD does not replace prenatal testing, such as chorionic villus sampling or amniocentesis. PGD is a research-based test allowing for a similar diagnosis to those available by prenatal testing. However, prenatal testing is still recommended, as this is currently the standard of care. Our doctors can discuss what prenatal testing options are available to you.