[1] McMaster Univ, Div Maternal Fetal Med, Dept Obstet, Hamilton, ON L8S 4K1, Canada
[2] McMaster Univ, Div Maternal Fetal Med, Dept Gynecol, Hamilton, ON L8S 4K1, Canada
[3] McMaster Univ, Dept Clin Epidemiol & Biostat, Hamilton, ON L8S 4K1, Canada
[4] McMaster Univ, Div Gen Pediat, Dept Pediat, Hamilton, ON L8S 4K1, Canada
[5] McMaster Univ, Div Neonatol, Dept Pediat, Hamilton, ON L8S 4K1, Canada
[6] St Josephs Healthcare, Father Sean OSullivan Res Ctr, Ctr Evaluat Med, Hamilton, ON, Canada
[7] St Josephs Healthcare, Father Sean OSullivan Res Ctr, Biostat Unit, Hamilton, ON, Canada
[8] Better Outcomes Registry & Network BORN Ontario, Toronto, ON, Canada
[9] Pontificia Univ Catolica Chile, Escuela Med, Div Obstet & Ginecol, Santiago, Chile