1. Department of Obstetrics and Gynaecology, Medical Research Center Oulu, Research Unit of Clinical Medicine, University of Oulu and Oulu University Hospital , FI-90029, Oulu , Finland
2. Institute of Reproductive and Developmental Biology, Imperial College London, W12 0NN , London , United Kingdom
3. Faculty of Medicine, Center for Life Course Health Research, University of Oulu , FI-90014, Oulu , Finland
4. Unit of Primary Care, Oulu University Hospital , FI-90220, Oulu , Finland
5. Department of Epidemiology and Biostatistics, School of Public Health, MRC Centre for Environment and Health, Imperial College London , W2 1PG, London , United Kingdom
6. Department of Life Sciences, College of Health and Life Sciences, Brunel University London , UB8 3PH, London , United Kingdom