Each year, 450,000 Canadian women become pregnant and, as a result of prenatal screening for Down syndrome, ~10,000 of them will have an amniocentesis; Of those tested, 315 will be found to carry a baby with Down syndrome and 70 normal pregnancies will be lost from complications of amniocentesis. This project will validate the use of next generation genomic technology to detect and analyze fetal DNA in circulating in maternal blood and determine whether the fetus has Down syndrome. The introduction of genomic blood testing in the context of this project could lead to increased detection of Down syndrome, less invasive screening and preventing losses due to current testing procedures. The project will also develop an evidence-based cost-effective approach for implementation of this new technology in the Canadian health care system and develop education and decision-making tools for future parents and health care professionals.