title: Higher cesarean delivery rates are associated with higher infant mortality rates in industrialized countries.
abstract: BACKGROUND
  Recent data indicate that more than half of high-income industrialized countries have a cesarean delivery rate of  > 25 percent, which is higher than the appropriate level considered by most health professionals worldwide.
  
  
  METHODS
  Data for 31 high-income industrialized countries in 2010 (or the nearest year) obtained from the World Health Organization, Organization for Economic Cooperation and Development, World Bank, and individual countries were analyzed in this study. We examined the correlation between cesarean delivery rate and infant mortality rate with Pearson correlation coefficient analysis, and examined the independent effect of cesarean delivery on infant mortality with multiple linear regression analyses.
  
  
  RESULTS
  The cesarean delivery and infant mortality rates varied substantially among the included countries: from 15.6 to 50.0 percent and from 1.9 per to 6.8 per 1,000 live births, respectively. Cesarean delivery rates were positively correlated with infant mortality rates (Pearson correlation coefficient: 0.41, p < 0.05). The association remained after adjustment for maternal age, infant sex, per capita GDP, and the Gini index (p < 0.03), but disappeared after further adjustment for preterm birth (p = 0.07). In a sensitivity analysis, the results were not appreciably affected by excluding births at < 22 weeks of gestation, by weighting the data by the number of births in each country, or by excluding data from particular countries with possible measurement issues (USA, Greece).
  
  
  CONCLUSIONS
  A higher cesarean delivery rate is associated with higher infant mortality rate among these high-income industrialized countries. One of the mechanisms by which cesarean delivery affects infant mortality is through iatrogenic prematurity.
authors.affiliation: Department of Nursing at the Hunan University of Medicine, Huaihua, China; McLaughlin Centre for Population Health Risk Assessment, Institute of Population Health, University of Ottawa, Ottawa, ON, Canada.
authors.forename: Ri-Hua
authors.initials: RH
authors.lastname: Xie
authors.forename: Laura
authors.initials: L
authors.lastname: Gaudet
authors.forename: Daniel
authors.initials: D
authors.lastname: Krewski
authors.forename: Ian D
authors.initials: ID
authors.lastname: Graham
authors.forename: Mark C
authors.initials: MC
authors.lastname: Walker
authors.forename: Shi Wu
authors.initials: SW
authors.lastname: Wen
mesh_terms: D002585:Cesarean Section / Q000706:statistics & numerical data*; D019049:Developed Countries / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D007223:Infant; D007226:Infant Mortality; D007231:Infant, Newborn; D016014:Linear Models; D008297:Male; D011247:Pregnancy
keywords: cesarean delivery; high-income countries; infant mortality