Chiguru Adivasi Birth cohort study: A protocol for examining the effects of parental substance use on child development in southern Indian Adivasi communities.

Background Children of parents who use tobacco and alcohol are at risk of adverse emotional, social, behavioural and cognitive outcomes, and of malnutrition. The co-occurrence of a high malnutrition burden and rising substance use may sustain ongoing and intergenerational developmental disadvantage. Evidence on how postnatal parental substance exposure affects longitudinal child health and development in Adivasi (Indigenous) communities remains a substantial knowledge gap. This is the first large-scale Adivasi birth cohort designed to prospectively examine the associations of substance use by parents and family members with child growth and developmental outcomes in southern Karnataka’s Adivasi communities. Method A prospective longitudinal cohort follows infants from birth to three years of age. Parents and co-resident family members are invited to participate. Substance use (alcohol and tobacco) is recorded as the exposure variable at baseline and at the 3, 6, 12, 24 and 36 month follow-up visits. The primary outcomes are child growth parameters (stunting, wasting and underweight). Secondary outcomes are early childhood development across the gross motor, fine motor, language and social domains, assessed using the Malawi Development Assessment Tool (MDAT). Information on socio-demographics, household wealth index, family diet, mental health, child immunisation, family morbidity, chronic conditions and social support is collected concurrently. We aim to recruit 650 newborns and their families (2023–2027). Discussion This prospective cohort study quantifies the longitudinal associations of parental tobacco and alcohol consumption with child growth and developmental outcomes in southern Indian Adivasi communities. Co-measured risk factors, including household wealth, diet, air pollution and parental mental health, will contextualise these outcomes. The maximum follow-up period is three years. The study addresses the historical underrepresentation and neglect of research within Adivasi populations and fosters long-term research collaboration with the participating communities. It aims to provide evidence to policymakers regarding substance use, health challenges, and child growth and development.