Low birthweight infants (under 2500 g) are much more likely to have severe diseases or die in the first year of life. This study's objective was to compare occurrence of low birthweight, preterm births, and intrauterine growth retardation in two cohorts born in the years 1982 and 1993 in Pelotas, Southern Brazil. All hospital births (corresponding to over 99% of total births) were evaluated for both years. Low birthweight increased from 9.0% in 1982 to 9.8% in 1993 (p=0.2), preterm births increased from 5.6% to 7.5% (p<0.01), and intrauterine growth retardation increased from 15.0% in 1982 to 17.5% in 1993 (p<0.05). In the two years under study, family income was inversely associated with low birthweight and intrauterine growth retardation, but not with preterm births. Compared to 1982, mothers in the 1993 birth cohort had better socioeconomic and nutritional status, as well as better coverage of prenatal care. However, these improvements were not expressed as a decrease in low birthweight. On the contrary, after the possible confounding effects of socioeconomic and nutritional variables were controlled, risk of low birthweight in 1993 was 33% higher than that of 1982 (p<0.01).
Low Birthweight; Child Health; Epidemiology; Growth; Nutrition
