[Risk factors associated with very low birth weight in a low-income population]

This study aimed to identify risk factors associated with very low birth weight in a general hospital in Caxias do Sul, Rio Grande do Sul State, Brazil. This was a case-control study of 200 newborns with birth weight from 500 to 1,499 g (cases) and 400 with birth weight from 3,000 to 3,999 g (controls). Infants were from singleton pregnancies, and their mother had received prenatal care at public health services. The dependent variable was birth weight, and independent variables included socioeconomic status, schooling, and gestational and birth status. Univariate and multivariate analyses were performed with a 5% level of significance. Mortality in very low birth weight newborns was 32.5%. The limits of viability were 600 g for birth weight and 26 weeks for gestational age. Variables related to very low birth weight were: maternal age > 35 years (p = 0.01), lack of prenatal care (p < 0.0001), illness during the index pregnancy (p = 0.03), maternal hypertension (p = 0.007), hospitalization during pregnancy (p < 0.0001), and prior history of low birth weight (p < 0.0001). Many premature births were due to avertable factors.