Interpretation of antenatal screening methods.

Park, In Yang; Kwon, Ji Young; Shin, Jong Chul

Review

Korean Journal of Obstetrics & Gynecology 2009;52(2):157-165.
Published online February 1, 2009.

Interpretation of antenatal screening methods.

In Yang Park, Ji Young Kwon, Jong Chul Shin

Department of Obstetrics and Gynecology, College of Medicine Catholic University of Korea, Seoul, Korea. jcshin@catholic.ac.kr

Abstract

For definitive antenatal diagnosis of fetal aneuploidy, invasive tests such as chorionic villous sampling, amniocentesis and cordocentesis are required for chromosome analysis. However, to reduce the risk of miscarriage associated with procedural complications, it is important to detect pregnant women with high risk of fetal aneuploidy. Recently, there have been advances in maternal serum and sonographic markers for screening of chromosomal defects in the first and second trimester. The serum screening methods include first trimester screening with nuchal translucency and second trimester multi marker screening. Particularly, combining first and second trimester results can increase the detection rate of Down syndrome with lower false-positive rates. In addition to biochemical markers, second trimester sonogram to detect major and minor sonographic markers for chromosomal defects is important to identify the high risk pregnancy. To detect the fetal aneuploidy with high specificity and sensitivity, we need to interpret the maternal age, the results of first and second trimester serum markers and genetic sonographic findings all together.

Key Words: Fetal aneuploidy, First trimester screening, Second trimester screening, Genetic sonography