title: Maternal anxiety during pregnancy and adverse birth outcomes: a systematic review and meta-analysis of prospective cohort studies.
abstract: BACKGROUND
  Previous studies concerning the association between maternal anxiety during pregnancy and adverse birth outcomes have provided controversial findings.
  
  
  METHODS
  In this systematic review, a meta-analysis was utilized to investigate the association between maternal anxiety and preterm birth (PTB) and/or low birth weight (LBW). Literature was searched until June 2013. Only prospective cohort studies that reported data on maternal anxiety during pregnancy with PTB and/or LBW were included. Pooled relative risks (RRs) with 95% conﬁdence intervals (CIs) were calculated using fixed or random effects models depending on the size of heterogeneity.
  
  
  RESULTS
  Twelve studies totaling 17,304 pregnant women reported PTB data; and six studies totaling 4948 pregnant women reported LBW data. Maternal anxiety during pregnancy was associated with significant increased risk of PTB (pooled RR=1.50, 95% CI=1.33-1.70) and LBW (pooled RR=1.76, 95% CI=1.32-2.33).
  
  
  CONCLUSIONS
  Potential moderators could not be adequately considered due to insufficient information. In addition, the effects of different types of anxiety disorder on the risk of these adverse birth outcomes could not be investigated.
  
  
  CONCLUSIONS
  The results suggested that maternal anxiety during pregnancy was positively related to an increased risk of PTB and LBW. Healthcare providers should give close attention to anxiety in pregnant women and provide appropriate mental health support in order to improve outcomes for both mothers and infants.
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei 230032, Anhui, China.
authors.forename: Xiu-Xiu
authors.initials: XX
authors.lastname: Ding
authors.affiliation: Department of Epidemiology and Statistics, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China.
authors.forename: Yi-Le
authors.initials: YL
authors.lastname: Wu
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei 230032, Anhui, China. Electronic address: xushaojun@ahmu.edu.cn.
authors.forename: Shao-Jun
authors.initials: SJ
authors.lastname: Xu
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei 230032, Anhui, China.
authors.forename: Ruo-Ping
authors.initials: RP
authors.lastname: Zhu
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei 230032, Anhui, China.
authors.forename: Xiao-Min
authors.initials: XM
authors.lastname: Jia
authors.affiliation: Department of Obstetrics and Gynecology, Maternal and Child Health Hospital of Anhui Province, Hefei 230001, Anhui, China.
authors.forename: Shi-Fen
authors.initials: SF
authors.lastname: Zhang
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei 230032, Anhui, China.
authors.forename: Kun
authors.initials: K
authors.lastname: Huang
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei 230032, Anhui, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Zhu
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei 230032, Anhui, China.
authors.forename: Jia-Hu
authors.initials: JH
authors.lastname: Hao
authors.affiliation: Department of Maternal, Child and Adolescent Health, School of Public Health, Anhui Medical University, No. 81 Meishan Road, Hefei 230032, Anhui, China; Anhui Provincial Key Laboratory of Population Health & Aristogenics, Hefei 230032, Anhui, China.
authors.forename: Fang-Biao
authors.initials: FB
authors.lastname: Tao
mesh_terms: D001007:Anxiety / Q000453:epidemiology*; D005260:Female; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D011247:Pregnancy; D037841:Pregnant People / Q000523:psychology*; D047928:Premature Birth / Q000453:epidemiology*; D011446:Prospective Studies; D012306:Risk
keywords: Anxiety; Birth weight; Pregnancy; Preterm