RT Journal Article SR Electronic T1 Surge in Down syndrome prenatal testing anticipated JF Canadian Medical Association Journal JO CMAJ FD Canadian Medical Association SP E449 OP E450 DO 10.1503/cmaj.109-4170 VO 184 IS 9 A1 Collier, Roger YR 2012 UL http://www.cmaj.ca/content/184/9/E449.abstract