1. Department of Obstetrics and Gynaecology, County Hospital of Östersund
2. Department of Obstetrics and Gynaecology, University of Lund
3. Department of Obstetrics and Gynaecology, Huddinge University, Karolinska Institutet
4. Department of Paediatrics, St Görans Hospital, Karolinska Institutet, Sweden
5. Department of Laboratory Medicine, Osaka City University Medical School, Japan