Prenatal screening gives parents-to-be information about whether their fetus has certain genetic disorders.
Genetic disorders are caused by changes in a person’s genes or chromosomes. Aneuploidy is a condition in which there are missing or extra chromosomes. In a trisomy, there is an extra chromosome. In a monosomy, a chromosome is missing. Inherited disorders are caused by changes in genes called mutations. Inherited disorders include sickle cell disease, cystic fibrosis, Tay–Sachs disease, and many others. In most cases, both parents must carry the same gene to have an affected child.
This testing can be done in conjunction with an elective 3D Ultrasound.
There are two general types of prenatal tests for genetic disorders:
- Prenatal screening tests: These tests can tell you the chances that your fetus has an aneuploidy and a few additional disorders.
- Prenatal diagnostic tests: These tests can tell you whether your fetus actually has certain disorders. These tests are done on cells from the fetus or placenta obtained through amniocentesis or chorionic villus sampling (CVS).
Both screening and diagnostic testing are offered to all pregnant women.