Floods and heatwaves are becoming more frequent and intense and can disrupt routine maternal and child health (MCH) services. Previous reviews have not systematically examined how context and mechanisms may shape adaptation outcomes. This realist-informed systematic review examines how, why and under what conditions interventions support access to, utilisation of and continuity of routine MCH services during flood and heat events.

The search strategy was developed by integrating terms from 17 related reviews, refined with the author team and checked by an experienced London School of Hygiene & Tropical Medicine librarian. The initial database search was conducted on 16 May 2025 and the search was updated on 30 April 2026. Eight databases were searched: Web of Science, Ovid MEDLINE, EMBASE, Global Health, EconLit, GreenFILE, CINAHL and ProQuest Environmental Science & Public Policy. Records published between January 2000 and April 2026 were eligible. Search results were imported into EndNote and deduplicated. Title-and-abstract screening and full-text assessment were conducted independently by two reviewers for the initial search and are ongoing for the updated search, with ASReview being used to prioritise records during title-and-abstract screening. Data extraction across the full review evidence base remains ongoing using a structured template covering study context, intervention characteristics, mechanisms, outcomes, costs and implementation conditions. Study settings will be classified by country income group, health system context and Köppen–Geiger climate zone to compare evidence across settings and, where appropriate, to identify possible climate analogues for exploratory, context-specific assessment. Climate-zone similarity will not be used to infer intervention transferability or future effectiveness. The synthesis will be guided by the WHO Climate-Resilient Health Systems framework, Meadows’ leverage-points framework and realist-informed C–M–O reasoning. Interventions will be grouped to identify where they operate within the health system and which health system components and vulnerabilities they address. Findings will be reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidance.

Ethical approval is not required because the review uses published literature and does not involve human participants. The findings will be disseminated through a peer-reviewed systematic review publication. They will inform the design, improvement and scaling of interventions intended to maintain routine MCH services and strengthen health system resilience to floods and heatwaves across diverse settings.

The review was not prospectively registered with PROSPERO.

To collate and appraise evidence from existing systematic reviews and meta-analyses on interventions to prevent stillbirth and reduce perinatal mortality across the reproductive continuum, including preconception, antenatal, intrapartum and immediate newborn periods.

Umbrella review synthesising evidence from systematic reviews, including meta-analyses where available.

A comprehensive search was conducted in CENTRAL (via Cochrane Register of Studies Online), PubMed, Embase and Web of Science, along with trial registries (WHO International Clinical Trials Registry Platform, ClinicalTrials.gov and ISRCTN Registry), from inception to 12 January 2026.

Systematic reviews and meta-analyses synthesising randomised controlled trials or quasi-experimental studies that reported stillbirth, perinatal mortality, fetal loss or fetal death were included. Reviews focused exclusively on predefined high-risk populations were excluded.

Two reviewers independently extracted data and assessed methodological quality using A Measurement Tool to Assess Systematic Reviews 2 (AMSTAR 2). Grading of Recommendations, Assessment, Development and Evaluation (GRADE) certainty ratings were extracted as reported by the original review authors. Evidence synthesis followed a structured framework adapted from Ota et al, integrating direction of effect and certainty of evidence based on pooled estimates and GRADE assessments. Publication overlap was assessed using the Corrected Covered Area index where relevant.

A total of 116 systematic reviews were included, synthesising evidence from randomised controlled and quasi-experimental studies across preconception, antenatal, intrapartum and immediate newborn periods. Evidence from individual reviews showed clear benefit for several interventions, including balanced energy-protein supplementation, home visits by community health workers, birth preparedness interventions, labour induction at or beyond 37 weeks of gestation and skilled or community-based intrapartum care, primarily for reducing perinatal mortality. Reduced antenatal visit schedules compared with standard care were associated with a possible increase in stillbirth or perinatal mortality, indicating potential harm. Many interventions—such as group antenatal care (ANC), nutritional education, case-note provision, routine ultrasound or Doppler monitoring, antibiotic treatment for bacterial vaginosis, antiretroviral therapy in pregnancy and several pharmacological or hormonal interventions—demonstrated unknown or inconclusive effects on stillbirth or perinatal mortality, largely due to imprecision and heterogeneity.

This umbrella review identifies a range of interventions with evidence of effectiveness across the reproductive continuum, particularly those addressing maternal nutrition, continuity of ANC and quality intrapartum and newborn care. However, substantial evidence gaps remain, especially for interventions widely implemented without strong supporting evidence. These findings highlight the need for context-specific implementation research and prioritisation of proven strategies in low- and middle-income countries, where the burden of stillbirth remains highest.

CRD42024531100.