1. Department of International Health, Institute of General Practice and Community Medicine, University of Oslo, Postboks 1130, Blindern 0318, Norway; Department of Obstetric and Gynecology, Rikshospitalet University Hospital,
University of Oslo, Oslo N-0027, Norway; Kilimanjaro Christian Medical Centre, PO Box 3010, Moshi, Tanzania
2. Department of International Health, Institute of General Practice and Community Medicine, University of Oslo, Postboks 1130, Blindern 0318, Norway
3. Department of Obstetric and Gynecology, Rikshospitalet University Hospital, University of Oslo, Oslo N-0027, Norway
4. Department of International Health, Institute of General Practice and Community Medicine, University of Oslo, Postboks 1130, Blindern 0318, Norway; Kilimanjaro Christian Medical Centre, PO Box 3010, Moshi, Tanzania
5. Kilimanjaro Christian Medical Centre, PO Box 3010, Moshi, Tanzania
6. College of Health Sciences, Clinical Epidemiology Unit, University of Zimbabwe Medical School, PO Box A178, Avondale, Harare, Zimbabwe