妊娠中の母親の微量栄養素の状態とその南アジアの乳児への神経発達への影響：系統的レビューのプロトコル

Pregnancy is a crucial stage characterized by an increased demand for various nutrients. The role of micronutrients becomes especially important during pregnancy and infancy to support neurodevelopment. Micronutrient deficiencies are prevalent in low- and middle-income countries due to socioeconomic disparities, limited dietary diversity, and barriers to quality antenatal care. This results in women of reproductive age and developing offspring being disproportionately affected. Despite extensive research, evidence remains fragmented, leading to a lack of comprehensive synthesis.

This scoping review aims to explore the existing evidence on the role of maternal micronutrient status during pregnancy influencing neurodevelopmental outcomes in infants. Additionally, it will assess the prevalence and distribution of specific micronutrient deficiencies and identify their sociodemographic determinants within South Asian countries.

This scoping review uses an iterative, three-step search strategy to identify both published and gray literature. Initially, a targeted search using relevant keywords was developed for PubMed to locate studies investigating maternal micronutrient status or supplementation during pregnancy (women aged 15-49 y) and associated neurodevelopmental outcomes in offspring up to two years of age. The search was sequentially narrowed by geographic region (South Asian countries), study design, human studies, English-language publications, and clinical trials. In the second stage, this search strategy will be adapted and implemented across additional electronic databases, including MEDLINE, Embase, Google Scholar, Cochrane Library, OpenGrey, JSTOR, and Wiley, as well as trial registries such as ClinicalTrials.gov and PROSPERO. Further, supplementary hand-searching of relevant journals will be conducted. The third step involves applying a snowballing technique to review the bibliographies of initially identified papers. Two reviewers will independently conduct study selection and data extraction using standardized forms. Quality assessment will use Joanna Briggs Institute critical appraisal checklists. Quantitative findings (study characteristics, exposure definitions, outcome measures) will be summarized with descriptive statistics and visualized in structured tables and charts, and qualitative findings will be coded inductively to develop themes pertinent to the review questions. We will integrate evidence through a convergent narrative synthesis to contextualize how maternal micronutrient deficiencies are influenced by sociodemographic factors and how these relate to infant neurodevelopment. The review will adhere to PRISMA-ScR reporting guidelines.

The initial database search was completed on July 3, 2025. Title and abstract screening is in progress, and final synthesis and reporting are anticipated by January 2026.

This review aims to summarize the available evidence on maternal micronutrients and infant neurodevelopment in South Asia, identify major gaps and inconsistencies in the data, and highlight opportunities for focused research and multisectoral action. The findings will help guide the next phases of the South Asia Collaborative for Maternal Micronutrients and Infant Neurodevelopment (SACMIND) collaborative project, which will include qualitative studies, biomarker assessments, and designing interventions.