1. Institut national de santé publique du Québec , Montréal, Québec, Canada
2. Research Centre of the University of Montréal Hospital Centre , Montréal, Québec, Canada
3. Department of Social and Preventive Medicine, University of Montréal , Outremont, Québec, Canada
4. Department of Public Health and Epidemiology, University of Pierre and Marie Curie , Paris, France
5. Department of Obstetrics and Gynecology, Sainte-Justine Hospital, University of Montréal , Montréal, Québec, Canada