1. Division of Feto-Maternal Medicine, Department of Obstetrics and Gynecology, Medical University of Vienna, 1090 Vienna, Austria
2. Division of Neonatology, Pediatric Intensive Care and Neuropediatrics, Department of Pediatrics, Medical University of Vienna, 1090 Vienna, Austria
3. Department of Epidemiology, Center for Public Health, Medical University of Vienna, 1090 Vienna, Austria
4. Department of Cancer Epidemiology and Prevention Research, Alberta Health Services, Calgary, AB T2S 3C3, Canada
5. Departments of Oncology and Community Health Sciences, University of Calgary, Calgary, AB T2S 3C3, Canada