title: Risk factors for preterm premature rupture of membranes in Chinese women from urban cities.
abstract: OBJECTIVE
  To investigate the prevalence of preterm premature rupture of membranes (PPROM) in urban areas in China and examine the associated risk factors.
  
  
  METHODS
  A population-based, prospective study was undertaken in 14 cities in China between January 1, 2011, and January 31, 2012. Women were recruited at their first prenatal-care visit, when maternal characteristics were recorded. Risk factors were analyzed by one-way analysis of variance.
  
  
  RESULTS
  Of 112 439 women included in analyses, 3077 (2.7%) had PPROM. Univariate analysis showed an increased risk of PPROM before 28weeks of pregnancy in migrant women (odds ratio [OR] 2.25; 95% confidence interval [CI] 1.53-3.30; P<0.001), in those with a history of recurrent induced abortions (OR 2.75; 95% CI 1.66-4.56; P<0.001), and in those with a history of preterm birth (OR 3.90; 95% CI 0.77-19.61; P<0.001). The associations were maintained in multivariate analysis (P<0.001).
  
  
  CONCLUSIONS
  Migration as a result of urbanization, high rates of induced abortion, and preterm birth are potential risk factors for PPROM in Chinese women.
authors.affiliation: Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China; The Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai, China.
authors.forename: Qiongjie
authors.initials: Q
authors.lastname: Zhou
authors.affiliation: Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China.
authors.forename: Weiyuan
authors.initials: W
authors.lastname: Zhang
authors.affiliation: Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China; The Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Xu
authors.affiliation: Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China; The Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai, China.
authors.forename: Huan
authors.initials: H
authors.lastname: Liang
authors.affiliation: Beijing Obstetrics and Gynecology Hospital, Capital Medical University, Beijing, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Ruan
authors.affiliation: Department of Pharmaceutical Sciences, College of Pharmacy, University of South Florida, Tampa, FL, USA.
authors.forename: Shufeng
authors.initials: S
authors.lastname: Zhou
authors.affiliation: Obstetrics and Gynecology Hospital, Fudan University, Shanghai, China; The Shanghai Key Laboratory of Female Reproductive Endocrine-Related Diseases, Shanghai, China; Institute of Biomedical Sciences, Fudan University, Shanghai, China. Electronic address: xiaotianli555@163.com.
authors.forename: Xiaotian
authors.initials: X
authors.lastname: Li
mesh_terms: D000028:Abortion, Induced / Q000009:adverse effects; D000328:Adult; D000704:Analysis of Variance; D002681:China / Q000453:epidemiology; D002947:Cities / Q000453:epidemiology; D005260:Female; D005322:Premature Rupture of Fetal Membranes / Q000453:epidemiology* / Q000209:etiology*; D005865:Gestational Age; D006801:Humans; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology; D015995:Prevalence; D011446:Prospective Studies; D012307:Risk Factors; D014171:Transients and Migrants / Q000706:statistics & numerical data; D014505:Urban Population / Q000706:statistics & numerical data*
keywords: Chinese people; Epidemiology; Induced abortion; Migrants; Preterm premature rupture of membranes (PPROM); Urbanization