Methods
This study used a randomized controlled trial design and was conducted from October 2010 to February 2011 at the
health centers of Ghaemshahr, Iran. Women in the study
were randomly assigned to the interventional or control
groups from eight health centers. In order to prevent crosscontamination
through informal information sharing by the
intervetion group, the health centers were randomly allocated
by the cluster randomization to intervention (four
centers) and control (four centers) group. In each health