Diagnostic tests either confirm or help rule out the existence of chromosomal abnormalities. Because they are invasive tests, generally they are performed only after a screening test has identified a high risk for a particular condition, although some people will choose these tests based on their own circumstances. If you are in need of this type of testing, you will be referred to a Maternal Fetal Medicine specialist (high risk OB doctor).

Chronic Villus Sampling (CVS) or Amniocentesis

These tests require sampling tissue from the placenta or some of the amniotic fluid to evaluate for chromosomal abnormalities.