[1] McMaster Univ, Dept Obstet & Gynecol, Hamilton, ON, Canada
[2] McMaster Univ, Dept Hlth Res Methods Evidence & Impact, Hamilton, ON, Canada
[3] Univ Toronto, Dept Obstet & Gynecol, Div Maternal Fetal Med, Toronto, ON, Canada
[4] Univ Toronto, Dept Pediat, Div Neonatol, Toronto, ON, Canada
[5] McMaster Univ, Dept Radiol, Hamilton, ON, Canada
[6] McMaster Univ, Div Maternal Fetal Med, Hamilton, ON, Canada
[7] McMaster Univ, Dept Obstet & Gynecol, Div Maternal Fetal Med, Radiol & Hlth Res Methods,Evidence & Impact, 1280 Main St West,Room 3N52B, Hamilton, ON L8S 4K1, Canada