1. Department of Obstetrics and Gynecology, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
2. Children’s Hospital, Helsinki University Hospital and University of Helsinki, Helsinki, Finland
3. Department of Bacteriology, University of Helsinki and Helsinki University Hospital, HUSLAB, Helsinki, Finland
4. Department of Oral and Maxillofacial Diseases, Helsinki University Hospital, Institute of Dentistry, University of Helsinki, Helsinki, Finland
5. Division of Periodontology, Department of Dental Medicine, Karolinska Institutet, Huddinge, Sweden
6. Medix Biochemica, Espoo, Finland