[Probability of dying in the first year of life in an urban area of southern Brazil]. / Probabilidade de morrer no primeiro ano de vida em área urbana da região sul, Brasil.

ABSTRACT

PIP: A birth cohort of 4876 children born alive in 7 hospitals in an urban area of southern Brazil was selected and followed through up to the age of one year, with a view to estimating the risk of dying in the first year of life. Information on death was collected from death certificates. A total of 103 deaths were located in Maringa, of which 97 occurred in 1989. All of them were born in 1989, and the only requirement for belonging to the cohort was that of residence in the area. The selected variables were: sex, birth weight (low, adequate, and normal), age at moment of death (neonatal, late neonatal, and post neonatal) underlying cause of death (according to the International Classification of Diseases--9th Revision), and maternal age. The estimated probability of dying in the first year was of 19.9 per 1000 (77.3% of the deaths occurred during the neonatal period) in contrast with the official rate of 22.6/1000. The probability of dying in late infancy was 4.5/1000 compared to 15.4 in neonatal age. Perinatal causes and congenital malformations contributed to 80% of the deaths, and infectious diseases were the underlying cause of death in only 1.1% of the losses. 63.8% of infant deaths were caused by ailments acquired in the perinatal period, yielding a probability of death of 12.3/1000. The risk of a female infant dying was 1.4 higher than that of a male. The risk of dying in the fist year of life owing to ailments arising during the perinatal period was higher among vaginally delivered babies (20.3 per 1000) than it was for those born by caesarian section (9 per 1000). A higher probability of death was present among infants born to adolescent mothers, and those with low birth weight (less than 2500 g). The results signify the need to improve the quality of prenatal and infant care, and suggest the possible association between high infant mortality and lower socioeconomic level.