Screening for down syndrome in the United States: results of surveys in 2011 and 2012

Participants in a College of American Pathologists external proficiency testing program for first and second trimester Down syndrome screening. To determine the number of women screened for Down syndrome in the United States, along with the type of test received and to compare those results to earlier surveys in 1988 and 1992. Questionnaires regarding the type and number of Down syndrome tests performed per month were completed by participants in early 2011 and again in early 2012. After accounting for some of the missing responses, data from up to 131 laboratories indicated that 67% (2 764 020 of 4 130 000) to 72% (2012: 2 963 592 of 4 130 000) of US pregnancies received prenatal screening for Down syndrome. Second trimester tests were most common (2012: 60%; 1 770 024 of 2 963 592), followed by integrated (2012: 21%; 627 876 of 2 963 592), and first trimester (2012: 19%; 565 692 of 2 963 592). The 6 largest laboratories tested 61% of screened pregnancies and offered the widest array of tests, while the smallest 32 tested 1% and almost always offered only second trimester tests. The current population estimate of 72% pregnancies screened annually is higher than estimates from 1988 (25%) and 1992 (50%). Available testing choices are also more varied, and all testing methods perform better than those methods available 10 years ago. Clinicians should ensure that women are offered tests that follow recommended best-practice testing protocols, and screening laboratories should assess whether patient needs are being met.