1. National Perinatal Epidemiology Center, Anu Research Center, Department of Obstetrics and Gynecology, Cork University Maternity Hospital, Wilton, Cork, Ireland
2. Department of Epidemiology and Public Health and Department of Statistics, University College, Cork, Ireland
3. Department of International Health, University of Tampere, Tampere, Finland
4. Center for International Health, University of Bergen, Bergen, Norway