1. VU University Medical Center; Department of Midwifery Science, AVAG and the EMGO Institute for Health and Care Research; Amsterdam Netherlands
2. VU University Medical Center; Department of Public and Occupational Health, EMGO Institute for Health and Care Research; PO Box 7057 Amsterdam Netherlands 1007 MB
3. The University of Liverpool; Cochrane Pregnancy and Childbirth Group, Department of Women's and Children's Health; First Floor, Liverpool Women's NHS Foundation Trust Crown Street Liverpool UK L8 7SS
4. Geboortes & Zo; Primary Care Midwifery Practice; Joan Mirostraat 7 Utrecht Netherlands 3544NS
5. "University G. D'Annunzio" Foundation; Department of Medicine and Aging; Centre for Aging Sciences (Ce.S.I.), Internal Medicine Unit; via dei Vestini 31 Chieti Italy 66013
6. Radboud University Nijmegen Medical Centre; Department of Primary and Community Care, Women's Studies Medicine; Geert Grooteplein 21 P.O. Box 9101 Nijmegen Netherlands 6500 HB