Low birthweight, prematurity, and intrauterine growth restriction: results from the baseline data of the first indigenous birth cohort in Brazil (Guarani Birth Cohort)

Abstract

Abstract Background Low birthweight (LBW) remains an important global health problem, associated with a range of adverse life-course health outcomes. Evidence suggests that LBW is a relevant determinant of morbidity and mortality in indigenous groups, who generally have limited access to public policies on health and nutrition. Knowledge of the prevalence of LBW and its underlying causes can contribute essential steps to the prevention of its health effects. The study aimed to estimate the prevalence rates of LBW, prematurity, and intrauterine growth restriction (IUGR) and to investigate their determinants in the first indigenous birth cohort in Brazil. Methods This cross-sectional study used baseline data collected from the first indigenous birth cohort in Brazil, the Guarani Birth Cohort. Brazil is one of the most ethnically diverse countries in the world, with 305 indigenous peoples and 274 native languages. The Guarani are one of the five largest ethnic groups, with villages located mostly in the southern region. All singleton births from June 1, 2014, to May 31, 2016, were selected in 63 Guarani indigenous villages in the South and Southeast regions. Hierarchical multiple logistic regression was performed. Results Prevalence rates for LBW, prematurity, and IUGR were 15.5, 15.6, and 5.7%, respectively. The odds of LBW were lower in newborns of mothers living in brick and mortar housing (OR: 0.25; 95%CI: 0.07–0.84) and were higher in children of mothers ≤20 years of age (OR: 2.4; 95%CI: 1.29–4.44) and with chronic anemia before pregnancy (OR: 6.41; 95% CI: 1.70–24.16). Prematurity was statistically associated with the type of energy source for cooking (wood-burning stove – OR: 3.87; 95%CI: 1.71–8.78 and bonfires – OR: 2.57; 95%CI: 1.31–5.01). IUGR was associated with primiparity (OR: 4.66; 95%CI: 1.68–12.95) and chronic maternal anemia before pregnancy (OR: 7.21; 95%CI: 1.29–40.38). Conclusions Maternal age, nutritional status, and parity, housing conditions, and exposure to indoor pollution were associated with perinatal outcomes in the Guarani indigenous population. These results indicate the need to invest in access to, and improvement of, prenatal care; also in strengthening the Indigenous Healthcare Subsystem, and in inter-sector actions for the development of housing policies and sanitation and environmental improvements adjusted to needs and knowledge of the indigenous people.