Sonja Henderson, Cochrane Pregnancy and Childbirth Group, Department of Women's and Children's Health, Institute of Translational Medicine, The University of Liverpool, Liverpool Women's NHS Foundation Trust, Crown Street, Liverpool, L8 7SS, UK. email@example.com. firstname.lastname@example.org.
Reason for withdrawal from publication
This review has been withdrawn because it has been updated by a new review entitled 'Choice of instruments for assisted vaginal delivery'.