[Low birth weight in Brazil according to live birth data from the Ministry of Health, 2005].

Although the Brazilian Information System on Live Births (SINASC) has expanded its coverage and improved its data quality since the system was implemented, the live birth count in Brazil is still not complete. The current study analyzes inequalities in low birth weight in Brazil in 2005, based on geographic factors, municipality of residence, maternal schooling, and prenatal care. An analysis of all live births showed a low birth weight paradox, namely high percentages in areas with the highest socioeconomic development. The main explanation for these paradoxical findings involves shorter neonatal survival and inadequate recording of premature births in poorer municipalities. Considering at-term live births from non-multiple gestations, inequalities were found in maternal schooling. Comprehensive, quality prenatal care could have a greater impact by reducing negative outcomes of gestation and decreasing the socioeconomic inequalities of perinatal health in Brazil.