1. The Generation R Study Group Erasmus University Medical Center Rotterdam the Netherlands
2. Department of Pediatrics Erasmus University Medical Center Rotterdam the Netherlands
3. Division of Respiratory Medicine and Allergology, Department of Pediatrics Erasmus University Medical Center Rotterdam the Netherlands
4. Department of Obstetrics and Gynecology Erasmus University Medical Center Rotterdam the Netherlands
5. Division of Neonatology, Department of Pediatrics Erasmus University Medical Center Rotterdam the Netherlands