Prevalência e fatores associados à prematuridade em usuárias do sistema único de saúde

Abstract

Objective: To determine the prevalence of preterm birth and identify associated factors in users of Primary Health Care. Methods: A cross-sectional study was conducted between December 2022 and December 2024 with women ≥12 years old and children up to 24 months old, followed up at five Basic Health Units in Passo Fundo, RS. Data were collected through face-to-face interviews. The outcome was self-reported preterm birth. The exposures analyzed were sociodemographic, behavioral, maternal clinical, and prenatal-related variables. Descriptive and bivariate analyses (chi-square test, p<0.05) and Poisson regression with crude and adjusted prevalence ratios were performed. Results: 367 postpartum women participated, predominantly aged 20 to 34 years, with a significant presence of comorbidities, low levels of physical activity, and adequate prenatal care coverage. The prevalence of prematurity was 12.3% (95% CI: 9.1–16.1). In the adjusted analysis, the following were associated with the outcome: lower education (≥10 years as a protective factor; PR=0.47; 95% CI: 0.27–0.83), higher income (intermediate tertile PR=2.28; 95% CI: 1.04–5.04; upper tertile PR=3.33; 95% CI: 1.51–7.34), <6 prenatal visits (PR=2.84; 95% CI: 1.34–6.07), ≥2 pre-gestational comorbidities (PR=2.51; 95% CI: 1.31–4.80), pre-eclampsia (PR=3.46; 95% CI: 1.32–9.07) and excessive gestational weight gain (PR=0.45; 95% CI: 0.22–0.94). Conclusion: Prematurity was of significant magnitude and was mainly associated with clinical factors and inadequate prenatal care, reinforcing the need to improve care in Primary Health Care in order to prevent prematurity and its resulting complications.