Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Meta-Analysis
. 2014 Apr 1;179(7):807-23.
doi: 10.1093/aje/kwt334. Epub 2014 Feb 10.

Systematic review and meta-analysis of miscarriage and maternal exposure to tobacco smoke during pregnancy

Beth L Pineles, Edward Park, Jonathan M Samet
Meta-Analysis

Systematic review and meta-analysis of miscarriage and maternal exposure to tobacco smoke during pregnancy

Beth L Pineles et al. Am J Epidemiol. .

Abstract

We conducted a systematic review and meta-analysis to characterize the relationship between smoking and miscarriage. We searched the PubMed database (1956-August 31, 2011) using keywords and conducted manual reference searches of included articles and reports of the US Surgeon General. The full text of 1,706 articles was reviewed, and 98 articles that examined the association between active or passive smoking and miscarriage were included in the meta-analysis. Data were abstracted by 2 reviewers. Any active smoking was associated with increased risk of miscarriage (summary relative risk ratio = 1.23, 95% confidence interval (CI): 1.16, 1.30; n = 50 studies), and this risk was greater when the smoking exposure was specifically defined as during the pregnancy in which miscarriage risk was measured (summary relative risk ratio = 1.32, 95% CI: 1.21, 1.44; n = 25 studies). The risk of miscarriage increased with the amount smoked (1% increase in relative risk per cigarette smoked per day). Secondhand smoke exposure during pregnancy increased the risk of miscarriage by 11% (95% CI: 0.95, 1.31; n = 17 studies). Biases in study publication, design, and analysis did not significantly affect the results. This finding strengthens the evidence that women should not smoke while pregnant, and all women of reproductive age should be warned that smoking increases the risk of miscarriage.

Keywords: abortion; miscarriage; pregnancy; smoking; tobacco.

PubMed Disclaimer

Figures

Figure 1.
Figure 1.
Selection of studies included in the systematic review and meta-analysis of smoking and risk of miscarriage.
Figure 2.
Figure 2.
Forest plot for the association of any active maternal smoking and risk of miscarriage (150). Gray boxes represent the weight of the study in the meta-analysis. Studies with asterisks have odds ratios (ORs) presented; studies without asterisks have relative risks (RRs) presented. Bars, 95% confidence intervals (CIs).
Figure 3.
Figure 3.
Relative risk of miscarriage versus number of cigarettes smoked per day.
Figure 4.
Figure 4.
Funnel plot for studies that analyzed any active smoking and the risk of miscarriage. OR, odds ratio; RR, relative risk.
Figure 5.
Figure 5.
Forest plot for the association between maternal secondhand smoke exposure and risk of miscarriage (150). Gray boxes represent the weight of the study in the meta-analysis. Studies with asterisks have odds ratios (ORs) presented; studies without asterisks have relative risks (RRs) presented. Bars, 95% confidence intervals (CIs).
Figure 6.
Figure 6.
Forest plot for the cumulative meta-analysis of any active maternal smoking and risk of miscarriage (150). Studies are sorted chronologically in order of publication date, and each point represents the summary relative risk ratio (RRR) including all studies published before and including the study listed on the corresponding line. Bars, 95% confidence intervals (CIs).
See this image and copyright information in PMC

References

    1. US Department of Health and Human Services. The Health Consequences of Involuntary Exposure to Tobacco Smoke: A Report of the Surgeon General. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, Coordinating Center for Health Promotion, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2006.
    1. US Department of Health and Human Services. The Health Consequences of Smoking: A Report of the Surgeon General. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, Coordinating Center for Health Promotion, National Center for Chronic Disease Prevention and Health Promotion, Office on Smoking and Health; 2004.
    1. US Department of Health and Human Services. National Health and Nutrition Examination Survey Data. Vol 2010. Hyattsville, MD: US Department of Health and Human Services, Centers for Disease Control and Prevention, National Center for Health Statistics; 2010.
    1. US Department of Health and Human Services. BRFSS Annual Survey Data: Survey Data and Documentation. Atlanta, GA: US Department of Health and Human Services, Centers for Disease Control and Prevention, Office of Surveillance, Epidemiology, and Laboratory Services, Public Health Surveillance Program Office; 2011.
    1. Tong VT, Jones JR, Dietz PM, et al. Trends in smoking before, during, and after pregnancy—Pregnancy Risk Assessment Monitoring System (PRAMS), United States, 31 sites, 2000–2005. MMWR Surveill Summ. 2009;58(4):1–29. - PubMed

Publication types

Substances