The increasing trend in preterm birth in public hospitals in northern Argentina

Abstract

Objective: To identify factors associated with the increasing incidence of preterm birth in northern Argentina. Methods: In an observational study, data were reviewed from a prospective, population-based registry of pregnancy outcomes in six cities in 2009-2012. The primary outcome was preterm birth (at 20-37 weeks). Bivariate tests and generalized estimating equations were used within a conceptual hierarchical framework to estimate the cluster-corrected annual trend in odds of preterm birth. Results: The study reviewed data from 11 433 live births. There were 484 (4.2%) preterm births. The incidence of preterm births increased by 38% between 2009 and 2012, from 37.5 to 51.7 per 1000 live births. Unadjusted risk factors for preterm birth included young or advanced maternal age, normal body mass index, nulliparity, no prenatal care, no vitamins or supplements during pregnancy, multiple gestation, and maternal hypertension or prepartum hemorrhage. The prevalence of many risk factors increased over the study period, but variations in these factors explained less than 1% of the increasing trend in preterm birth. Conclusion: The incidence of preterm births insix small cities in northern Argentina increased greatly between 2009 and 2012. This trend was unexplained by the risk factors measured. Other factors should be assessed in future studies.