[1] Univ Toronto, Div Maternal Fetal Med, Dept Obstet & Gynecol, Sunnybrook Hlth Sci Ctr, Toronto, ON, Canada
[2] Univ Toronto, North York Gen Hosp, Dept Obstet & Gynecol, Toronto, ON, Canada
[3] Dalhousie Univ, Dalhousie Med Sch, Halifax, NS, Canada
[4] North York Gen Hosp, Genet Program, Toronto, ON, Canada
[5] Better Outcomes Registry & Network BORN Ontario, Prenatal Screening Ontario, Ottawa, ON, Canada
[6] Univ Toronto, Dept Obstet & Gynecol, Toronto, ON, Canada