Tehran University of Medical Sciences Iranian Journal of Public Health 2251-6085 55 3 2026 10 04 41243 41243 Tayebeh Mokhtari Sorkhani M.SC in Counseling in Midwifery, Instructor of Midwifery, Nursing & Midwifery Faculty, Bam University of Medical Sciences, Bam, Iran. Mahshid Bokaie Research Center for Nursing and Midwifery Care, Comprehensive Research Institute for Maternal and Child Health, Department of Midwifery, School of Nursing and Midwifery, Shahid Sadoughi University of Medical Sciences, Yazd, Iran Farzan Madadizadeh Medical Informatics Research Center, Institute for Futures Studies in Health, Kerman University of Medical Sciences, Kerman, Iran Manoj Sharma Professor, Department of Social and Behavioral Health, School of Public Health, University of Nevada, Las Vegas, USA & Department of Internal Medicine, Kirk Kerkorian School of Medicine at UNLV, Las Vegas, USA Seyed Saeed Mazloomy Mahmoodabad Social Determinants of Health Research Center, Non-Communicable Diseases Research Institute, Department of Health Education and Health Promotion, School of Public Health, Shahid Sadoughi University of Medical Sciences, Yazd, Iran 2025 10 23 2026 02 01 Background Childbearing decisions are influenced by psychological, social, and environmental factors. This study examined the predictive role of Multi-Theory Model (MTM) constructs in initiating and sustaining childbearing behavior among women with a single child. Methods A descriptive study was conducted in 2025 with 400 women who had one child. Demographic data and MTM constructs were collected via a structured questionnaire. Data were analyzed using SPSS version 21. Analyses included descriptive statistics, normality tests (Kolmogorov–Smirnov and Shapiro–Wilk), Spearman correlations, and multiple regression with bootstrapping, with significance set at p < 0.05.  Results Participants showed moderate to moderately high levels across MTM constructs. Behavioral confidence was the only significant predictor of initiation of childbearing (β = 0.34, p < 0.001, R² = 0.145), whereas transformational emotions significantly predicted the sustenance of behavior (β = 0.26, p < 0.001, R² = 0.168). Other constructs, including social environment and practice for change, contributed positively but were not significant. Correlation analyses confirmed that behavioral confidence and transformational emotions had the strongest associations with both initiation and continuation of childbearing behavior. Conclusion Behavioral confidence and emotional transformation play central roles in initiating and sustaining reproductive and childbearing behavior, while environmental and social factors have secondary influence. These findings support the applicability of MTM in reproductive health research and inform theory-based interventions to promote childbearing among women of reproductive age. https://ijph.tums.ac.ir/index.php/ijph/article/view/41243