Prenatal Screening Ontario (Dougan, Okun, Bellai-Dussault, Meng, Huang, Reszel, Lanes, Walker, Armour), Better Outcomes Registry & Network (BORN) Ontario; Children's Hospital of Eastern Ontario (CHEO) Research Institute (Dougan, Bellai-Dussault, Howley, Reszel, Walker, Armour), Ottawa, Ont.; Mount Sinai Hospital (Okun); Genetics Program (Huang), North York General Hospital; Department of Obstetrics and Gynecology (Huang), University of Toronto, Toronto, Ont.; Department of Obstetrics and Gynecology (Walker), University of Ottawa; Ottawa Hospital Research Institute (OHRI) (Walker); Department of Pediatrics (Armour), University of Ottawa, Ottawa, Ont.