1. EPI-Unit; Institute of Public Health, University of Porto; Porto Portugal
2. The Generation R Study Group, Erasmus MC, University Medical Center; Rotterdam The Netherlands
3. Department of Pediatrics; Erasmus MC, University Medical Center; Rotterdam The Netherlands
4. Department of Epidemiology; Erasmus MC, University Medical Center; Rotterdam The Netherlands
5. Department of Clinical Epidemiology, Predictive Medicine and Public Health; University of Porto Medical School; Porto Portugal