Infant Mortality in a Brazilian Municipality with a High Human Development Index

The aims were to study the time course and underlying causes of deaths in children under 1 year of age in a high Human Development Index municipality. We also sought to define the relationship between the timing of death and the neonatal age range and observed the extent to which deaths were avoidable.

Retrospective study of women living in the city of Niterói, Brazil, between 2012 and 2018. Data were collected from death certificates provided by hospitals. The chi-square test was used for categorical variables, while continuous variables were first analyzed descriptively (mean, standard deviation), followed by parametric or non-parametric methods.

A total of 455 deaths were recorded, with a normal distribution over time (P = .120). The mean age at death was 212.70 days [30 weeks = 7.5 months], with 17 children dying before age 28 days (3.7%). The sample was predominantly male (55.6%) and white (48.4%). The average gestational age was 31.2 weeks and the average birth weight was 1733.95 g, with 305 infants weighing < 2499 g (70.1%). Bacterial sepsis ([International Classification Diseases-10 P36.9]; n = 35; 7.7%) was the most commonly cited cause of death. International Classification Diseases-10 Chapters XVI (conditions-perinatal period [P00-P96]; n = 229; 50.3%) predominated. Infants who died in the neonatal period had a lower mean gestational age (P < .001) and weight (P < .001) compared to post-neonatal deaths.

Infant mortality has remained stable at tolerable levels in this municipality. Sepsis remains the leading cause of death, and mortality is directly associated with prematurity/ low birth weight, a multifactorial problem.