1. Department of Women's and Children's Health; Karolinska Institutet; Stockholm Sweden
2. Centre for Occupational and Environmental Medicine, Stockholm County Council; Stockholm Sweden
3. Department of Medicine; Karolinska Institutet; Stockholm Sweden
4. Department of Clinical Epidemiology and Biostatistics; Örebro University; Örebro Sweden
5. Department of Epidemiology and Public Health; University College London; London United Kingdom
6. Institute of Environmental Medicine; Karolinska Institutet; Stockholm Sweden