| Affiliation: | 1. Department of Epidemiology, Rollins School of Public Health, Emory University, , Atlanta, GA, USA;2. Department of Obstetrics and Gynaecology, Kuopio University Hospital, , Kuopio, Finland;3. Department of Anaesthesia and Operative Services, Kuopio University Hospital, , Kuopio, Finland;4. School of Medicine, University of Eastern Finland, , Kuopio, Finland;5. National Institute for Health and Welfare (THL), , Helsinki, Finland;6. Nordic School of Public Health, , Gothenburg, Sweden |
