[Multifactorial analysis of risk factors for low birth weight in Salvador, Bahia]

This study is a multifactorial analysis of the risk factors for low birthweight in a group of newborns in an urban area of Brazil. A total of 1023 infants born in four maternity units in Salvador, Bahia, between July 1987 and February 1988 were included in the study. The sources of information were clinical histories and interviews with the mothers in the maternity units. The analysis was by means of logistic regression. In the final model the risk factors were the following: maternal age less than 21 years or more than 35; gestational age less than 38 weeks; unfavorable outcome of an earlier pregnancy; interval of 12 months or less since prior birth; tobacco smoking; and hypertension. The population attributable risk values for the risk factors included in the final model are presented. These factors should be used to identify pregnant women at high risk of giving birth to a low-birthweight baby, in order to provide them with more prenatal care.