title: Cesarean sections in Piauí State: trend and associated factors in the period 2000-2011, Brazil.
abstract: to analyze trends in cesarean sections proportion and associated factors in Piauí State, Brazil, from 2000 to 2011.
  
  
  
  this is a time series and cross-sectional study, with data of all institutional childbirths in primiparous, recorded on the Information System on Live Births (Sinasc).
  
  
  
  cesarean sections proportion increased from 34.4% in 2000 to 52.1% in 2011 (annual percentage change +4.4; 95%CI 3.6;5.1); white-skinned women (PR=1.72; 95%CI 1.63;1.86), over 40 years (PR=2.17; 95%CI 2.09;2.28), with more than 12 years of schooling (PR=1.86; 95%CI 1.77;1.96), who attended 7 or more prenatal care appointments (PR=2.08; 95%CI 1.97;2.18), residents in municipalities with over 300,000 inhabitants (PR=1.68; 95%CI 1.62;1.80) and with higher Human Development Index (PR=1.61; 95%CI 1.51;1.73) presented the highest cesarean sections proportion.
  
  
  
  the occurrence of cesarean sections was high and more frequent in women with low obstetric risk.
authors.affiliation: Universidade Estadual do Piauí, Núcleo de Pesquisa e Extensão em Saúde da Mulher, Teresina-PI, Brasil.
authors.forename: Alberto
authors.initials: A
authors.lastname: Madeiro
authors.affiliation: Universidade Estadual do Piauí, Núcleo de Pesquisa e Extensão em Saúde da Mulher, Teresina-PI, Brasil.
authors.forename: Andréa Cronemberger
authors.initials: AC
authors.lastname: Rufino
authors.affiliation: Universidade Estadual do Piauí, Núcleo de Pesquisa e Extensão em Saúde da Mulher, Teresina-PI, Brasil.
authors.forename: Aline Oliveira Dos
authors.initials: AO
authors.lastname: Santos
mesh_terms: D000328:Adult; D001938:Brazil; D002585:Cesarean Section / Q000706:statistics & numerical data* / Q000639:trends; D002947:Cities; D003430:Cross-Sectional Studies; D036861:Delivery, Obstetric / Q000706:statistics & numerical data*; D005260:Female; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D011295:Prenatal Care / Q000706:statistics & numerical data*; D012307:Risk Factors; D055815:Young Adult