Editing Prenatal testing (section)

====Carrier screening  ====
Carrier screening is a general DNA test that uses a blood or cheek swab sample to determine if the parents carry certain genetic conditions. This test can be done anytime, whether the individual(s) are considering starting a family or have already become pregnant. Various types of carrier screens are available that test for progressively more genetic abnormalities. The single gene/condition screen will test for a specific condition, whereas, the expanded carrier screen will test for hundreds of different abnormalities that can be inherited by a fetus. There are also three gene/condition and ethnic specific carrier tests. In the case of a positive test result, further testing is often recommended, as the carrier test only determines if the parent(s) is a carrier, not if the gene has definitively been passed to the fetus.<ref name="www.acog.org" />