1. Department of Obstetrics and Gynaecology, Medical Research Center Oulu, PEDEGO Research Unit, University of Oulu and Oulu University Hospital , Oulu, Finland
2. Department of Obstetrics and Gynaecology, University of Helsinki and Helsinki University Hospital , Helsinki, Finland
3. Center for Life Course Health Research, Faculty of Medicine, University of Oulu , Oulu, Finland
4. Unit of Primary Care, Oulu University Hospital , Oulu, Finland
5. MRC Centre for Environment and Health, Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London , London, UK
6. Department of Life Sciences, College of Health and Life Sciences, Brunel University London , London, UK
7. Institute of Reproductive and Developmental Biology, Imperial College London , London, UK