A systematic review of interventions during pregnancy and the postnatal period for parents in vulnerable life situations: evidence from high-income countries

Background Psychosocial vulnerabilities in parents during pregnancy, such as mental health challenges, limited social support, and adverse life experiences, can negatively affect maternal well-being, parent–infant attachment, and early child development. Interventions promoting parenting skills initiated early might mitigate these risks; however, evidence from high-income countries remains unclear. Methods We conducted a systematic review of randomised controlled trials published between 2000 and 2025 that targeted parents with psychosocial vulnerabilities in high-income countries and included interventions delivered by maternity care providers during pregnancy or within six months postpartum to promote parenting skills. Searches were conducted in four databases and supplemented by a review of grey literature. The studies were grouped by delivery modality, resource demand, and initiation time. We used the Cochrane Risk of Bias Tool for Randomised Trials and conducted a study-level confidence appraisal to contextualise each study’s contribution to the synthesis. Results Nine studies met the inclusion criteria. Studies included parents with mental health concerns, combinations of psychological and social risk factors, or primarily sociodemographic risk factors. Interventions varied in modality, resource demand, initiation time, content, and intended mechanisms. Across primary and secondary outcomes, most estimates did not provide clear evidence of intervention effects. Selected favourable findings concerned parenting knowledge, individual dimensions of parent–infant interaction and emotional availability, and parenting stress. Some reported effect estimates were small to moderate, but favourable findings were confined to selected outcomes and were often imprecise or arose from studies with important methodological limitations. No consistent intervention-favouring effect on depressive symptoms was identified. All studies were rated as having a high risk of bias in at least two key domains, and the study-level confidence appraisal indicated low or very low confidence in individual study contributions. Conclusions The evidence was limited and inconsistent and did not establish the effectiveness of these interventions. Selected favourable findings suggest potential benefits, but they do not show a coherent pattern of effectiveness. Given the small, heterogeneous evidence base and substantial methodological limitations, the findings should be interpreted cautiously. Larger, adequately powered, methodologically rigorous, and transparently reported trials informed by participant involvement and feasibility-testing are needed. Trial registration PROSPERO: reg.no: CRD420251016149.