[Birth weight and associated factors at baseline of an Indigenous birth cohort in Mato Grosso do Sul State, Brazil].

The aim of the present study was to investigate birth weight and associated factors among Indigenous peoples in the state of Mato Grosso do Sul, Brazil. A cross-sectional baseline study was conducted with an Indigenous birth cohort of 407 livebirths to Indigenous women living in villages, retaken territories, and urban communities between 2021 and 2022. Birth weight (in grams) was considered the main outcome, with means and 95% confidence intervals calculated according to maternal and household characteristics. A multiple linear regression model was run to determine associations between mean birth weight and maternal household, demographic, and obstetric characteristics, with a 95% confidence level. Mean birth weight was 3,160.5g. The prevalence of low birth weight and macrosomia was 6.4% and 3.7%, respectively. After the adjustment for confounding variables, lower birth weight was found among livebirths of women living in households with a communal outdoor faucet and those with insufficient gestational weight gain. Children with higher birthweights were found among women with excessive gestational weight gain and multiparous women. The birth weight of Indigenous children was associated with maternal nutritional status, multiparity, and limited access to drinking water, indicating the need to improve nutritional surveillance for Indigenous women of childbearing age and strengthen intersectoral public policies that ensure access to drinking water on Indigenous lands.