1. National, regional, and global prevalence of smoking during pregnancy in the general population: a systematic review and meta-analysis 
Shannon Lange, MPH, Charlotte Probst, PhD, Prof Jürgen Rehm, PhD, Svetlana Popova, PhD 
The Lancet Global Health 
Volume 6, Issue 7, Pages e769-e776 (July 2018)
DOI: /S X(18)
Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions

2. Figure 1 Study selection
The Lancet Global Health 2018 6, e769-e776DOI: ( /S X(18) )
Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions

3. Figure 2 Global prevalence of smoking during pregnancy in 2015
The Lancet Global Health 2018 6, e769-e776DOI: ( /S X(18) )
Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions

4. Figure 3
Proportion of pregnant women who smoked during pregnancy, by frequency and quantity, globally
Frequency was categorised as occasional smoking (at least one cigarette per occasion, but less than daily) or daily smoking (at least one cigarette every day). Quantity was categorised as light smoking (1–10 cigarettes per smoking day), moderate smoking (11–19 cigarettes per smoking day), and heavy smoking (≥20 cigarettes per smoking day).
The Lancet Global Health 2018 6, e769-e776DOI: ( /S X(18) )
Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions

5. Figure 4
Prevalence of daily smoking in women and pregnant women in the general population and estimated proportion of women who smoke daily who continue to smoke daily during pregnancy, by WHO region
The Lancet Global Health 2018 6, e769-e776DOI: ( /S X(18) )
Copyright © 2018 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY-NC-ND 4.0 license Terms and Conditions