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First-trimester combined test and integrated tests for screening for Down syndrome and trisomy 18

Geralyn M Messerlian, PhD
Antonio Farina, MD
Glenn E Palomaki, PhD
Section Editor
Louise Wilkins-Haug, MD, PhD
Deputy Editor
Vanessa A Barss, MD, FACOG


First-trimester and integrated screening tests for Down syndrome and trisomy 18 will be reviewed here. Other aspects of Down syndrome screening are discussed separately:

(See "Down syndrome: Overview of prenatal screening".)

(See "Laboratory issues related to maternal serum screening for Down syndrome".)

(See "Sonographic findings associated with fetal aneuploidy".)

A glossary of terms describing the various tests used in first- and second-trimester screening for Down syndrome is provided in the table (table 1).

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Literature review current through: Nov 2017. | This topic last updated: Aug 15, 2017.
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