IRCT2017030432876N1 IRCT 2017-03-27 Vice chancellor for Tarbiat Modares University The effect of theory-based educational intervention on behaviors of prenatal care The effect of theory-based educational intervention on behaviors of prenatal care in pregnant women referred to health centers in Iranshahr 2016-02-20 anticipated 90 Complete https://irct.ir/trial/25508 interventional Randomization: Randomized, Blinding: Not blinded, Placebo: Not used, Assignment: Parallel, Purpose: Prevention, Other design features: Sample size was equal to 90 pregnant women that were selected based on simple random sampling and were assigned to intervention group (n=45) and control group (n=45) by the random number table. 2 Prenatal care. Intervention 1: Intervention group of this study consisted of 45 pregnant women of Iranshahr city which four the intervention group, four sessions of 60 minutes was hold based on the theory (HBM and social support). Before the intervention, immediately after intervention, 3 and 6 months after the intervention, questionnaires were completed by the participants. Intervention 2: Control group of this study consisted of 45 pregnant women of Iranshahr city. Control group did not receive any intervention. Simultaneously with the intervention group, Before the intervention, immediately after intervention, 3 and 6 months after the intervention, questionnaires were completed by the participants.