Brazil is among the top ten countries in preterm delivery worldwide. This study assesses the factors associated with preterm birth in the Western Brazilian Amazon. A population-based cross-sectional study was held between July 2015 to June 2016 in Cruzeiro do Sul, Brazilian Amazon. A total of 1525 births were included in this analysis. Preterm birth was defined as births at gestational age < 37 weeks. A stepwise multiple logistic regression was used to identify factors associated with preterm delivery. The prevalence rate of preterm birth was 7.9% (n = 120; 95% CI: 6.5-9.3). After adjusting for confounding factors, a positive association with preterm birth was observed for pregnant women who completed less than six antenatal care visits (OR: 2.93; 95% CI: 1.89-4.56), who had a birth interval of < 18 months (OR: 2.65; 95% CI: 1.04-6.75), and who experienced bleeding (OR: 2.17; 95% CI: 1.39-3.38) and hypertension during pregnancy (OR: 1.74; 95% CI: 1.07-2.82). Factors associated with preterm birth in the Western Brazilian Amazon were mostly related to the aspects of health care provided to women, and thus could be prevented. Proper, timely, and regular antenatal care visits can help reduce adverse outcomes, such as hypertension and bleeding.
Keywords: Brazilian Amazon; Preterm birth; gestational age; pregnancy; prenatal care.