title: Prevalence of preterm labor in Iran: A systematic review and meta-analysis.
abstract: BACKGROUND
  Preterm labor, which defines as live-birth delivery before 37 weeks of gestation is a main determinant of neonatal morbidity and mortality around the world.
  
  
  OBJECTIVE
  The aim of this study was to determine the prevalence of preterm labor in Iran by a meta-analysis study, to be as a final measure for policy makers in this field.
  
  
  METHODS
  In this meta-analysis, the databases of Thomson database (Web of Knowledge), PubMed/Medline, Science Direct, Scopus, Google Scholar, Iranmedex, Scientific Information Database (SID), Magiran, and Medlib were searched for articles in English and Persian language published between 1995 and 2014. Among the studies with regard to the inclusion and exclusion criteria, 14 studies (out of 1370 publications) were selected. Data were analyzed by using Stata software version 11. The heterogeneity of reported prevalence among studies was evaluated by the Chi-square based Q test and I2 statistics.
  
  
  RESULTS
  The results of Chi-square based on Q test and I2 statistics revealed severe heterogeneity (Q=2505.12, p-value < 0.001 and I2= 99.5%) and consequently, the random effect model was used for the meta-analysis. Based on the random effect model, the overall estimated prevalence of preterm in Iran was 9.2% (95% CI: 7.6 - 10.7).
  
  
  CONCLUSIONS
  Present study summarized the results of previous studies and provided a comprehensive view about the preterm delivery in Iran. In order to achieve a more desirable level and its reduction in the coming years, identifying affecting factor and interventional and preventive actions seem necessary.
authors.affiliation: Faculty of Nursing and Midwifery, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Katayon
authors.initials: K
authors.lastname: Vakilian
authors.affiliation: Faculty of Nursing and Midwifery, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Mehdi
authors.initials: M
authors.lastname: Ranjbaran
authors.affiliation: Faculty of Nursing and Midwifery, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Mahboobeh
authors.initials: M
authors.lastname: Khorsandi
authors.affiliation: Faculty of Nursing and Midwifery, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Naser
authors.initials: N
authors.lastname: Sharafkhani
authors.affiliation: Faculty of Nursing and Midwifery, Arak University of Medical Sciences, Arak, Iran.
authors.forename: Mahmoud
authors.initials: M
authors.lastname: Khodadost
keywords: Iran; Meta-analysis; Preterm labor; Prevalence