Current methods of prenatal screening for Down syndrome and other fetal abnormalities.

Prenatal diagnosis of Down syndrome is widely available, but the determination of which patients should undergo prenatal diagnosis is changing. With the recent acceptance of first-trimester and integrated screening as a part of routine clinical practice, there are now a variety of accepted screening protocols for Down syndrome and other aneuploidies. These choices can be confusing both to both patients and providers. The following discussion is meant to outline the various options in prenatal screening, and their individual advantages and disadvantages.