Abstract
Early relational health during the first 24 months of life is a key determinant of child development and wellbeing. During this postnatal period, the parent–infant relationship plays a central role in emotional regulation, bonding, and developmental trajectories. Although the broader early relational health framework encompasses the first 1,000 days of life, this scoping review focuses specifically on the postnatal phase, where parent–infant interactions are directly observable and measurable. However, existing assessment instruments vary widely in their conceptual focus, scope, and characteristics, and no comprehensive review has systematically mapped tools used to assess the parent–infant relationship during early infancy. In response to this gap, a transdisciplinary working group within the COST Action CA22114 – TREASURE collaboratively developed a scoping review protocol to systematically map instruments assessing the parent–infant relationship from birth to 24 months of age. This Brief Report describes the collaborative methodological process underpinning the protocol’s development. The process followed an iterative, consensus-driven approach involving multidisciplinary experts from multiple COST member countries. Through structured online meetings, the group clarified core constructs and established the age range using the Population–Concept–Context (PCC) framework. The JBI methodology for scoping reviews was adopted and aligned with PRISMA-ScR standards to ensure transparency and reproducibility. Progressive drafting, internal peer review, and iterative refinement led to the final protocol, which was registered on the Open Science Framework (DOI: 10.17605/OSF.IO/HRVX9).The resulting protocol provides a replicable methodological framework for mapping instruments that assess the parent–infant relationship in the first two years of life. This Brief Report presents a framework for collaborative protocol development in international research networks, promoting shared knowledge generation in early relational health research and offering potential applicability to other COST initiatives.
Plain Language Summary
This article explains how an international team of researchers worked together to create a structured plan (protocol) for a scoping review, a type of research review that maps existing evidence. The aim of this review is to identify and describe the tools used to assess the relationship between parents and their babies during the first two years of life, a crucial period for emotional bonding, development, and long-term health. Experts from different countries within the COST network collaborated step by step to define key concepts, agree on suitable methods, and design a clear and transparent protocol. This protocol will guide a future scoping review that will identify and map all instruments used to evaluate the parent–infant relationship. The findings will help healthcare professionals, researchers, and policymakers better understand the range and characteristics of available instruments, supporting informed decisions about their use in promoting early relational health.
This project has received funding from the European Union’s Framework Programme for Research & Innovation as part of the COST Action (CA22114: TREASURE: Maternal Perinatal Stress and Adverse Outcomes in the Offspring: Maximising infant´s development), as supported by the COST Association (European Cooperation in Science and Technology).
The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
This work is licensed under a Creative Commons Attribution 4.0 International License.
Amendment
First, the Introduction has been refined to more clearly distinguish key constructs related to the parent–infant relationship, including bonding, attachment, interaction, and responsiveness. We now explicitly describe how these constructs were discussed during the early consensus-building stages and clarify how conceptual overlaps will be handled during data extraction and synthesis in the forthcoming scoping review.
Second, the rationale for focusing on the first 24 months of life has been expanded. The revised text provides a clearer developmental justification for this cutoff, linking it to critical postnatal transitions such as the consolidation of attachment patterns, increasing infant autonomy, and changes in interactional modalities. We also clarify the relationship between the broader “first 1,000 days” framework and the specific postnatal focus of this protocol.
Third, the manuscript more clearly positions the protocol in relation to existing reviews by emphasising its novelty as a comprehensive mapping of instruments across relational constructs within a defined developmental window, rather than focusing on isolated dimensions.
Fourth, the Discussion has been strengthened to better articulate the implications of mapping assessment instruments for early intervention, prevention, and evidence-informed practice. We also explicitly acknowledge the relevance of embodied and interaction-based dimensions of early relationships, while clarifying that vulnerable populations such as preterm infants fall outside the scope of the present protocol and represent an important direction for future research.
Finally, Figure 1 and its caption were expanded to more clearly distinguish standard scoping review development phases from network-specific collaborative elements.
