The association between smoking during pregnancy and hypertensive disorders of pregnancy: A systematic review and meta‐analysis
Jianing Wang, Wenbo Yang, Wenxuan Xiao, Shiyi Cao
Abstract
BACKGROUND: Smoking is a major public health problem. However, its association with hypertensive disorders of pregnancy (HDP) is inconclusive. OBJECTIVE: To find the association between smoking during pregnancy and HDP. SEARCH STRATEGY: We searched PubMed, Ovid and Cochrane Library up to March, 2021, using terms including "smoking" and "HDP". SELECTION CRITERIA: Observational studies that assessed the relationship between smoking during pregnancy and HDP were included. DATA COLLECTION AND ANALYSIS: Odds ratios (OR) and 95% confidence intervals (CI), and other necessary data were extracted. Stata16.0 MP was used to analyze statistics. MAIN RESULTS: A total of 13 studies were included. Meta-analysis revealed that smoking during pregnancy was a protective factor for HDP (OR 0.78, 95% CI 0.67-0.92), gestational hypertension (OR 0.74, 95% CI 0.69-0.79), and pre-eclampsia (OR 0.65, 95% CI 0.58-0.73). Subgroup analysis showed that smoking during pregnancy was a risk factor for HDP in Asia but a protective factor in Europe and North America. Neither quitting smoking before pregnancy nor during pregnancy had a statistically significant association with HDP. CONCLUSION: This meta-analysis revealed that smoking during pregnancy might prevent HDP, gestational hypertension, and pre-eclampsia. Smoking during pregnancy was a risk factor for HDP in Asia but a protective factor in Europe and North America.