1. Department of Clinical EpidemiologyAarhus University Hospital Aarhus Denmark
2. Department of Environmental Health SciencesYale School of Public Health New Haven CT USA
3. Yale Center for Perinatal, Pediatric, and Environmental EpidemiologyYale School of Public Health New Haven CT USA
4. Division of Epidemiology and Biostatistics, School of Public HealthUniversity of Illinois at Chicago Chicago IL USA
5. Department of Public Health, Section for EpidemiologyAarhus University Aarhus Denmark
6. Department of Public Health, Section for Environment, Occupation, and HealthAarhus University Aarhus Denmark