[1] McGill Univ, Hlth Ctr, Dept Pediat, 1001 Boul Decarie, Montreal, PQ H3J 2W8, Canada
[2] Mt Sinai Hosp, Maternal Infant Care Res Ctr, Toronto, ON, Canada
[3] Quebec Univ Laval, Ctr Hosp Univ, Dept Pediat, Quebec City, PQ, Canada
[4] McGill Univ, Dept Epidemiol Biostat & Occupat Hlth, Montreal, PQ, Canada
[5] Ctr Hosp Univ St Justine, Dept Pediat, Montreal, PQ, Canada
[6] Jewish Gen Hosp, Dept Neonatol, Montreal, PQ, Canada