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


CONCLUSIONS
The incidence of preterm births in six 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.
Carolina Population Center, University of North Carolina School at Chapel Hill, Chapel Hill, NC, USA. Electronic address: emweaver@email.unc.edu.
Emily H
EH
Weaver
Department of Mother and Child Health Research, Institute for Clinical Effectiveness and Health Policy, Buenos Aires, Argentina.
Luz
L
Gibbons
Department of Mother and Child Health Research, Institute for Clinical Effectiveness and Health Policy, Buenos Aires, Argentina.
José M
JM
Belizán
Department of Mother and Child Health Research, Institute for Clinical Effectiveness and Health Policy, Buenos Aires, Argentina.
Fernando
F
Althabe
D000328:Adult; D001118:Argentina / Q000453:epidemiology; D005260:Female; D006779:Hospitals, Public; D006801:Humans; D015994:Incidence; D007231:Infant, Newborn; D008423:Maternal Age; D011247:Pregnancy; D011248:Pregnancy Complications / Q000453:epidemiology*; D011256:Pregnancy Outcome; D047928:Premature Birth / Q000453:epidemiology*; D011295:Prenatal Care / Q000706:statistics & numerical data; D015995:Prevalence; D011446:Prospective Studies; D012042:Registries; D012307:Risk Factors; D055815:Young Adult
Argentina; Preterm birth; Trend