title: The association between uterine leiomyoma and placenta abruption: A meta-analysis.
abstract: BACKGROUND
  Some epidemiological studies have found that uterine leiomyoma can increase the risk of placenta abruption. To date, the meta-analysis has not been performed for assessing the relationship between uterine leiomyoma and placenta abruption. This meta-analysis was conducted to estimate the association between uterine leiomyoma and the risk of placenta abruption.
  
  
  METHODS
  A literature search was conducted out in major databases PubMed, Web of Science, and Scopus from the earliest possible year to October 2016. The heterogeneity across studies was explored by Q-test and I2statistic. The publication bias was assessed by Begg's and Egger's tests. The results were showed using odds ratio (OR) estimate with its 95% confidence intervals (CI) using a random-effects model.
  
  
  RESULTS
  The literature search included 953 articles until October 2016 with 232,024 participants. Based on OR estimates obtained from case-control and cohort studies, there was significant association between uterine leiomyoma and placenta abruption (2.63; 95% CI: 1.38, 3.88).
  
  
  CONCLUSIONS
  We showed based on reports in observational studies that uterine leiomyoma is a risk factor for placenta abruption.
authors.affiliation: a Department of Midwifery , Tuyserkan Branch, Islamic Azad University , Tuyserkan , Iran.
authors.forename: Ensiyeh
authors.initials: E
authors.lastname: Jenabi
authors.affiliation: b Faculty of Midwifery, School of Nursing and Midwifery , Mashhad University of Medical Sciences , Mashhad , Iran.
authors.forename: Samira
authors.initials: S
authors.lastname: Ebrahimzadeh Zagami
mesh_terms: D000037:Abruptio Placentae / Q000453:epidemiology* / Q000209:etiology; D016022:Case-Control Studies; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007889:Leiomyoma / Q000150:complications / Q000453:epidemiology*; D011247:Pregnancy; D011252:Pregnancy Complications, Neoplastic / Q000453:epidemiology; D012307:Risk Factors; D014594:Uterine Neoplasms / Q000150:complications / Q000453:epidemiology*
keywords: Placenta abruption; meta-analysis; pregnancy; uterine leiomyoma