1. Departments of Pediatrics and
2. Department of Environmental Health, National Institute for Health and Welfare, Kuopio, Finland;
3. Institute of Public Health and Clinical Nutrition, University of Eastern Finland, Kuopio, Finland; and
4. Institute of Epidemiology and Medical Biometry, University of Ulm, Ulm, Germany
5. Obstetrics and Gynecology, Kuopio University Hospital, Kuopio, Finland;