Sonographic markers used to detect frequent trisomies.

Trisomy 13, 18 and 21 are the 3 most prevalent chromosome abnormalities among newborns. A second trimester ultrasound is an important noninvasive method that can detect the anomalies. Sonographic markers have been correlated to each of the 3 trisomies. An increased knowledge and understanding of the different markers can improve detection of the different trisomies. The earlier the detection, the better clinical treatment can be adapted.