1. Population Health Program and
2. School of Midwifery, Laurentian University, Sudbury, Ontario, Canada;
3. Ottawa Hospital Research Institute, Ottawa, Ontario, Canada;
4. Departments of Epidemiology and Community Medicine and
5. Better Outcomes Registry & Network (BORN) Ontario, Ottawa, Ontario, Canada;
6. Obstetrics & Gynecology, University of Ottawa, Ottawa, Ontario, Canada;
7. Institute for Clinical Evaluative Sciences, Toronto, Ontario, Canada;
8. Division of Paediatric Medicine, Hospital for Sick Children, Toronto, Ontario, Canada; and
9. Department of Paediatrics and Institute of Health Policy and Management and Evaluation, University of Toronto, Toronto, Ontario, Canada