1. Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
2. Department of Infectious Disease Epidemiology, London School of Hygiene and Tropical Medicine, London, United Kingdom
3. Department of Obstetrics and Gynecology, Regional Hospital West Jutland, Herning, Denmark
4. Department of Clinical Medicine, Aarhus University, Aarhus, Denmark
5. Department of Obstetrics and Gynecology, Aarhus University Hospital, Aarhus, Denmark
6. Department of Epidemiology, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
7. Department of Gynecology and Obstetrics, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
8. Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
9. Division of Public Health Sciences, Washington University School of Medicine, St Louis, Missouri, USA
10. Center for Health Decision Science, Department of Health Policy and Management, Harvard T.H. Chan School of Public Health, Boston, Massachusetts, USA
11. Department of Biostatistics, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
12. Department of Epidemiology and Public Health, University of Maryland School of Medicine Baltimore, Maryland, USA