It has long been acknowledged that women with children require social support to promote their health and wellbeing, as well as that of their children. However, the dominant conceptualizations of support have been heavily influenced by Western family norms. The consequence, at best, has been to stifle our understanding of the nature and consequences of support for mothers and children. At worst, it has led to systematic discrimination negatively impacting maternal-child health. To fully engage with the complexities of social support, we must take multidisciplinary or interdisciplinary approaches spanning diverse cultural and geographical perspectives. However, multidisciplinary knowledge-processing can be challenging, and it is often unclear how different studies from different disciplines relate. To address this, we outline two epistemological frameworks-the scientific approach and Tinbergen's four questions-that can be useful tools in connecting research across disciplines. In this theme issue on 'Multidisciplinary perspectives on social support and maternal-child health', we attempt to foster multidisciplinary thinking by presenting work from a diverse range of disciplines, populations and cultures. Our hope is that these tools, along with papers in this issue, help to build a holistic understanding of social support and its consequences for mothers and their children. Overall, a multidisciplinary perspective points to how the responsibility of childrearing should not fall solely onto mothers. Indeed, this multidisciplinary issue demonstrates that successful childrearing is consistently an activity shared beyond the mother and the nuclear family: an insight that is crucial to harnessing the potential of social support to improve maternal-child health. This article is part of the theme issue 'Multidisciplinary perspectives on social support and maternal-child health'.