the effect of participating in the labor preparation classes on maternal vitality and positive affect during the pregnancy and after the labor

background : pregnant women predispose to physical and emotional diseases. vitality and positive affect are against the depression and low energetic mood exercise and physical activities in pregnancy have short and long term consequences for mothers and their growing fetus and affected in mood regulation. respiratory and relaxation skills could decrease stress, pain and use of analgesics during labor. methods : in this study, 117 primigravida and multigravida women (59 women in case and 58 in control groups) were enrolled. women in case group participated in delivery preparation classes since 20 weeks of pregnancy for 8 sessions. the control group was just received routine pregnancy care. the education was about pregnancy and delivery, physical exercises and relaxation skills. questionnaires of vitality and positive affect toward the labor were completed three times: before intervention, after the 8 th session and after delivery to 2 weeks later by an interview. data analyzed using spss 16 software and repeated measurement. results : there was a significant difference in vitality and positive affect regarding type of delivery before and after intervention and after delivery in case group(p < 0.0001).there was no significant difference in vitality and positive affect scores after delivery and  after intervention (p < 0.083, p < 0.545). there was significant difference in vitality and positive affect scores regarding between case and control groups after the intervention and after the delivery (p < 0.001, p < 0.0001). conclusions : considering the results of this study, it could be recommended that all pregnant women should contribute in delivery preparation classes to improve their mood, confidence, vitality toward labor. key words : labor preparation classes, vitality, positive effect, subjective wellbeing.