[1] Univ Toronto, Sunnybrook Hlth Sci Ctr, Dept Obstet & Gynaecol, Div Maternal Fetal Med, Toronto, ON, Canada
[2] Univ Barcelona, Inst Invest Biomed August Pi i Sunyer, Fetal ID Fetal Med Res Ctr,Hosp Clin Barcelona BC, Barcelona Ctr Maternal Fetal & Neonatal Med, Barcelona, Spain
[3] McMaster Univ, Dept Obstet & Gynaecol, Hamilton, ON, Canada
[4] McMaster Univ, Dept Hlth Res Methods Evidence & Impact, Hamilton, ON, Canada
[5] Univ Toronto, Mt Sinai Hosp, Dept Obstet & Gynaecol, Div Maternal Fetal Med, Toronto, ON, Canada
[6] Sunnybrook Hlth Sci Ctr, Dept Newborn & Dev Pediat, Toronto, ON, Canada
[7] Univ Toronto, Toronto, ON, Canada
[8] Sunnybrook Res Inst, Res Design & Biostat, Toronto, ON, Canada
[9] Hosp St Joan Deu Barcelona BCNatal, Barcelona Ctr Maternal Fetal & Neonatal Med, Barcelona, Spain