Down syndrome screening in the United States in 2001 and 2007: a survey of maternal-fetal medicine specialists

Objective The purpose of this study was to determine changes in screening and performance of invasive diagnostic procedures for Down syndrome between 2001 and 2007. Study Design The Society for Maternal-Fetal Medicine members completed a survey in 2007 regarding screening tests and diagnostic procedures for Down syndrome. With the use of descriptive statistics, the χ2 test, and the Student t test, responses from 2007 were compared with responses from a similar 2001 survey. Results Performance of first-trimester screening more than doubled from 2001-2007 (43.1% in 2001, 97.3% in 2007; P < .0001). Between 2001 and 2007, the use of the quad screen increased 10-fold (8.5% in 2001, 85.6% in 2007; P < .0001). There was an estimated 20% decrease in invasive diagnostic procedures that were performed in risk-positive women (53.7% in 2001, 34.2% in 2007; P < .0001). In 2007, the average fetal loss rates that were quoted by maternal-fetal medicine specialists after chorionic villous sampling was 1:160 and after an amniocentesis was 1:493. Conclusion Down syndrome screening evolved from 2001-2007, with an increasing emphasis on first-trimester screening. With more efficacious screening, the number of invasive procedures has declined.