1. Maternal, Child and Youth Health Division, Centre for Surveillance and Applied Research Public Health Agency of Canada Ottawa Ontario Canada
2. School of Epidemiology and Public Health University of Ottawa Ottawa Ontario Canada
3. Department of Biochemistry and Medical Genetics University of Manitoba Winnipeg Manitoba Canada
4. Nutrition Research Division, Bureau of Nutritional Sciences, Food Directorate, Health Products and Food Branch Health Canada Ottawa Ontario Canada
5. Division of Epidemiology and Biostatistics, Department of Obstetrics, Gynecology, and Reproductive Sciences Rutgers Robert Wood Johnson Medical School New Brunswick New Jersey
6. Department of Pediatrics McGill University Montreal Quebec Canada
7. Department of Epidemiology, Biostatistics and Occupational Health McGill University Montreal Quebec Canada
8. Department of Obstetrics and Gynaecology and the School of Population and Public Health, University of British Columbia and the Children's and Women's Hospital of British Columbia Vancouver British Columbia Canada