1. From the Maternal, Child and Youth Health Division, Centre for Surveillance and Applied Research, Public Health Agency of Canada, Ottawa, ON (S.L.)
2. Departments of Medicine and Obstetrics and Gynaecology, University of British Columbia, the Children’s and Women’s Hospital of British Columbia, Vancouver, BC (W.-S.C.)
3. Departments of Medicine, Health Policy Management and Evaluation and Obstetrics and Gynecology, St Michael’s Hospital, University of Toronto, ON (J.G.R.)
4. Departments of Pediatrics and of Epidemiology, Biostatistics and Occupational Health, McGill University, Montreal, QC (M.S.K.)
5. Department of Obstetrics and Gynaecology, the School of Population and Public Health, University of British Columbia and the Children’s and Women’s Hospital of British Columbia, Vancouver, BC, Canada (K.S.J.).