1. Department of Obstetrics & Gynecology; Division of Maternal Fetal Medicine; McMaster University; Hamilton ON Canada
2. Department of Obstetrics & Gynecology; University of Toronto; Toronto ON Canada
3. Department of Pediatrics; Division of Neonatology; Department of Health Policy, Management and Evaluation; University of Toronto; Toronto ON Canada
4. Department of Pediatrics; McMaster University; Hamilton ON Canada
5. Department of Epidemiology; Dalla Lana School of Public Health; University of Toronto; Toronto ON Canada
6. Department of Clinical Epidemiology & Biostatistics; McMaster University; Hamilton ON Canada