Background: Social connections are important during the transition to parenthood. A wide body of literature suggests that these connections enhance health and contribute to wellbeing. In the case of parents and families, social connections can influence child development. Nurses and public health agencies are in a unique position to advocate for resources and approaches to enhance social connectivity for parents during this important life transition. Objectives: The aim of this review was to identify the universal social connectivity interventions that work, and the conditions that foster social connections for parents and enhance child development. The review was undertaken as part of a larger research project to inform the question: What are the population-level interventions that public health can implement to promote social, emotional and cognitive development from the prenatal period to the end of the first year of life? Social connectivity is one of three domains that were explored in the full study. Design: Realist synthesis. Data sources: Medline, CINAHL, ERIC, SocAbs, PsychINFO, grey literature. Review methods: A literature search was conducted using relevant key words and MeSH headings. Nearly 2000 papers were reviewed by title and sorted based on inclusion and exclusion criteria. Data extraction aided quality appraisal and analysis and informed the development of an explanatory mechanism. Results: Twenty-seven papers were included in the synthesis, with findings described in four theme areas: (a) connections in the community, (b) internet connections, (c) prenatal connections, and (d) connections for fathers. The literature available to answer the research question is scant and of varying quality. Community development, family-systems intervention practices, principles of father inclusive practice and group prenatal care models have been demonstrated to foster social connectivity for parents. Online social networking provides valuable informational support. Conclusions: Changing social structures and technology have influenced the way in which new parents access support. Social connections fostered in the parenting environment have the potential to enhance wellbeing for parents and thus contribute to children's positive development. Nurses are in a position to advocate for the use of evidence-informed approaches when planning programs and services for parents. (C) 2017 The Authors. Published by Elsevier Inc.