1. Unit of PharmacoEpidemiology and PharmacoEconomics, Department of Pharmacy; University of Groningen; Groningen The Netherlands
2. University of Groningen, University Medical Center Groningen; Groningen The Netherlands
3. Department of Obstetrics and Gynaecology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
4. Department of Epidemiology; University of Groningen, University Medical Center Groningen; Groningen The Netherlands
5. Groningen Research Institute for Asthma and COPD (GRIAC); University of Groningen, University Medical Center Groningen; Groningen The Netherlands
6. Pediatric Pulmonology and Pediatric Allergology, Beatrix Children's Hospital; University of Groningen, University Medical Center Groningen; Groningen The Netherlands