1. Centre for Maternal and Child Health Research; City University London; London UK
2. INSERM; Obstetrical Perinatal and Paediatric Epidemiology Research Team; Centre for Epidemiology and Biostatistics (U1153); Paris-Descartes University; Paris France
3. Department of Child Health; TNO; the Netherlands Organisation for Applied Scientific Research; Leiden the Netherlands
4. Research Unit of Perinatal Epidemiology; Bambino Gesù Children's Hospital; Rome Italy
5. Department of Obstetrics and Gynaecology; GROW School of Oncology and Developmental Biology; Maastricht University Medical Centre; Maastricht the Netherlands
6. Perinatology Unit; University Medical Centre; Llubjana University; Llubjana Slovenia
7. Department of Obstetrics and Gynaecology; Landspitali University Hospital; Landspitali v/Hringbraut Iceland