Tendência da prevalência de nascimentos pré-termo na região Centro-Oeste do Brasil : um estudo de séries temporais

Abstract

Introduction: Preterm birth still persists as the major cause of the under-5 mortality rate in newborns in Brazil and worldwide. Preterm is defined as a child born alive before 37 weeks of pregnancy are completed. Prematurity is recognized as a multifactorial event, consequently, it is associated with sociodemographic, behavioral, environmental, clinical health conditions, and obstetric factors. Preterm is a serious public health problem since it affects the child, family, and society, for this reason, epidemiologic studies to monitor preterm births must be continuously conducted. However, there are few studies published on the magnitude and the trend of preterm rates in the Midwest of Brazil. Objective: Assessing the prevalence rates of preterm births in the Midwest of Brazil in a longterm time series. Methodology: We conducted a time-series study, population-based, using data on live births living in the Midwest’s federative units (Goiás, Mato Grosso, Mato Grosso do Sul, and the Federal District), from the Brazilian Information System on Live Births during 2001 to 2019. We calculated the preterm numbers by sex according to 100 g birth weight categories (a minimum of 0g to a maximum of 5000g) for the region and your federative units. Annual rates of preterm births/100 live births were estimated by place of the study. The Prais-Winsten generalized linear regression model was used to estimate the trend of the rates. In this model, the dependent variable was the logarithm with base 10 of annual rates of preterm births and the independent variable the years of the study. After estimating the regression coefficients of the rates, as an inverse process, the coefficients were exponentiated and multiplied by 100. Positive regression coefficients (increment) indicated increasing trends and negative coefficients, decreasing trends. In cases in which zero was inside the confidence interval (p> 0.05) the trends were considered stationary. A 95% confidence interval and a p-value less than 0.05 were adopted. The data were managed and analyzed in Stata v.12. Results: During 2001 to 2019 it was estimated 498,156 preterm newborns in the Midwest region, of which 103,291 (20.8%) living in Mato Grosso, 87,033 (17.4%) in Mato Grosso do Sul, 201,163 (40.4%) in Goiás and 106,669 (21.4%) in the Federal District. The annual rates of prevalence of preterm births were upward for the Midwest region and its federative units. The annual increase in rates was 0.51% (95% CI: 0.37-0.65, p=0.000) in Mato Grosso, 0.33% (95% CI: 0.21-0.45, p=0.000) in Mato Grosso do Sul, 0.25% (95% CI: 0.06-0.44, p=0.012) in the Federal District and 0.73% (95% CI: 0.54-0.91 , p=0.000) in Goiás. In the Midwest region the increase was 0.51% (95% CI: 0.37-0.65, p=0.000). Conclusion: In a long-term time series that comprised 19-year, the federative unit with the highest annual increase in the prevalence rates of preterm births was Goiás. By updating the prevalence rates of prematurity in the Midwest region, this study adds scientific information to support maternal and child health policies.