1. Department of Occupational and Environmental Medicine, Bispebjerg University Hospital, DK-2400 Copenhagen NV, Denmark
2. Molecular Reproductive Medicine, Department of Translational Medicine, Lund University, Sweden
3. Department of Public Health, Section of Social Medicine, University of Copenhagen, DK-1014 Copenhagen K, Denmark
4. Department of Obstetrics/Gynaecology, Hvidovre Hospital, Copenhagen University Hospital, DK-2650 Hvidovre, Denmark
5. Research Center for Prevention and Health (RCPH), University of Copenhagen, DK-2600 Glostrup, Denmark