1. Institute of Public Health, Department of Community Health, Kilimanjaro Christian Medical University College (KMUCO), P.O. Box 2240, Moshi, Tanzania
2. Better Health for African Mothers and Children (BHAMC) Project, P.O. Box 8418, Moshi, Tanzania
3. Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
4. Institute of Basic Medical Sciences, Faculty of Medicine, University of Oslo, Oslo, Norway
5. Ocean Road Cancer Institute, Directorate of Cancer Prevention Services, P.O. Box 3592, Dar es Salaam, Tanzania
6. Division of Gynaecology and Obstetrics, Oslo University Hospital, Rikshospitalet, 0863 Oslo, Norway
7. Department of Community Medicine, Kilimanjaro Christian Medical Centre (KCMC), Moshi, Tanzania