Definition: A test performed during pregnancy to look for possible genetic disorders in the developing fetus. A small sample of fluid surrounding the baby (amniotic fluid) is withdrawn through a needle inserted into the uterus. This fluid contains cells shed by the fetus, which can be tested in the laboratory. Amniocentesis is typically performed when an ultrasound or maternal blood test indicates a need for more information about the fetus’s development.
Source: Genetic and Rare Diseases (GARD) Information Center