1. Department of Obstetrics and Gynecology, University of Oulu, Oulu, Finland.
2. Clinic of Obstetrics and Gynecology, Oulu University Hospital, Oulu, Finland.
3. Institute of Health Sciences, University of Oulu, Oulu, Finland.
4. Department of Children, Young People, and Families, National Institute for Health and Welfare, Oulu, Finland.
5. Department of Chronic Disease Prevention, National Institute for Health and Welfare, Oulu, Finland.
6. Northern Finland Laboratory Centre Nordlab, Oulu University Hospital, Oulu, Finland.
7. Department of Clinical Chemistry, University of Oulu, Oulu, Finland.
8. Medical Research Center Oulu, Oulu University Hospital, Oulu, Finland.
9. Department of Epidemiology and Biostatistics, MRC Health Protection Agency (HPA) Centre for Environment and Health, School of Public Health, Imperial College London, United Kingdom.
10. PEDEGO Research Unit, Department of Child Psychiatry, University of Oulu, Oulu, Finland.
11. Department of Child Psychiatry, Oulu University Hospital, Oulu, Finland.