Background: Girl child marriage is increasingly recognized as a critical barrier to global public health and gender discrimination. There are still more gaps in the global rate of child marriage and the underlying factors. Thus, the present systematic review aimed to explore the prevalence of child marriage and the underlying factors. Methods: A comprehensive search was conducted for all English-language studies that measured the prevalence of child marriage and its correlates from 2000 to March 2022, indexed in PubMed, Scopus, Web of Science, Poplin, and Google Scholar databases. Child marriage is defined as marriage under the age of 18. In the present study, Joanna Briggs' quality assessment checklist was used for data collection. Two independent reviewers reviewed all the articles. Results: In total, 34 eligible prevalence articles and 14 trend articles were included in the study with data from 127,945 participants. The prevalence of child marriage ranged between 1.8% to 90.85%. In most studies, the trend of child marriage was decreasing. The most important individual factors include the respondent's education and occupation, interpersonal factors such as the education and occupation of parents and husband, family size and type. Community factors include socioeconomic status, region, residence, ethnicity, and religion at the social level. Conclusion: Despite a central focus of research and policies on interventions that decrease child marriage, this phenomenon is still prevalent in many places. Therefore, further specific interventions are required to improve education, reduce poverty and inequality. This may help achieve the 2030 Sustainable Development Goals.

Background: Child marriage is one of the public health challenges that has caused increasing concerns in the health and development system. Therefore, this research was conducted to identify individual and interpersonal factors influencing child marriage from the perspectives of stakeholders and informants. Method: This qualitative study was conducted using content analysis and an inductive approach from 2023 to 2024 in Bam city, Kerman, Iran. Thirty-six stakeholders (girls who have been married for 15 years, parents, husbands, and informants) were purposively selected. Data were collected through semi-structured interviews and analyzed using the Graneheim and Lundman approach, with the assistance of MAXQDA software. Results: After analyzing of the data, individual and interpersonal themes were emerged. The first theme of “individual factors” consisted of biological, psychological, and demographic category with four sub-categories including insufficient cognitive and inferential development, physiological and anatomical features, facing stressful factors in life, and demographic characteristics. The second theme of “interpersonal factors” consisted of family structure with four sub-categories including traditional parenting methods, family values, family breakup, Inefficiency of management and problem-solving in the family, and weak social capital in the family. The category of Ineffective interactions and social support also encompass two sub-categories: Peer pressure and reference groups, and inappropriate care and support relationship between teachers and students. Conclusion: The results showed that individual and interpersonal factors are effective on children’s marriage. Some individual factors have a biological origin, indicating that increasing girls’ awareness of marriage, pregnancy, individual rights, and life skills is one solution that can help reduce early marriage. On an interpersonal level, fostering positive relationships within the family, school, and society, and strengthening the support network can play a crucial protective role for children.