Mostwomen in the United States give birth to healthy babies. Despite this, many women worry about birth defects .
Some women are at higher risk than others for having a baby with a birth defect.
While not all birth defects can be detected before delivery, certain tests may find some birth defects during pregnancy. For these procedures, a sample is taken to be tested from either the amniotic fluid surrounding the fetus or the placenta. Amniocentesis and CVS can help identify chromosomal problems such as Down's syndrome or other genetic diseases such as cystic fibrosis, Tay-Sachs disease, and sickle cell disease. They can also be used to find out the sex of the fetus. The following topics are covered below.