Maternal anxiety during pregnancy and adverse birth outcomes: a systematic review and meta-analysis of prospective cohort studies.

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). LIMITATIONS: 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.