Down syndrome screening in the first, second or both trimesters?

Abstract

The aim of this article is to give an overview of current status of worldwide discussion of effectivness of Down's syndrome screeening programs. This article explaines structure of basic screening strategies and review of their published evidence.

In this article screening tests of the first trimester (combined test with or without new sonographic markers), the second trimester (quadruple, triple and double test) and tests which combine markes of the first trimester with markers of the second trimester (integrated test, sequential test and contingent tests) are discussed. Arguments supporting current trend to perform screening in the first trimester with combination ultrasound and biochemical markers of the first trimester are discussed.

Keywords

• Down syndrome
• screening strategies
• efficiency
• combined test
• integrated test
• biochemical screening
• ultrasound
• prenatal diagnostics