Maternal passive smoking during pregnancy and neural tube defects in offspring: a meta-analysis.
OBJECTIVE
This study aims to examine the association between maternal passive smoking during pregnancy and the occurrence of neural tube defects (NTDs) in offspring.


METHODS
We retrieved studies published on the association between maternal passive smoking during pregnancy and the occurrence of NTDs in offspring. Meta-analysis was applied to calculate the pooled effect estimates and their 95% confidence intervals (CIs) using data from 10 case-control studies. The publication bias was assessed by the Egger's regression asymmetry test and Begg's rank correlation test with Begg's funnel plot.


RESULTS
The pooled effect estimate of maternal passive smoking was 1.82 (95% CI 1.46-2.27) for total NTDs; the effect estimates were 1.72 (95% CI 1.44-2.06), 1.52 (95% CI 1.29-1.79), and 2.32 (95% CI 1.34-4.01) for NTDs subtypes of anencephaly, spina bifida and encephalocele, respectively. Stratified by geographic region of the studies, the pooled effect estimates were 2.11 (95% CI 1.46-3.06), 1.65 (95% CI 1.16-2.34), 1.25 (95% CI 0.41-3.80) in China, USA and Iran, respectively.


CONCLUSIONS
This meta-analysis suggested that maternal passive smoking during pregnancy was associated with an increased risk of total NTDs and three NTDs subtypes in offspring. Specifically, the associations were also found to be significantly positive both in China and USA.
Department of Epidemiology and Health Statistics, School of Public Health, Shandong University, 44 Wenhua Xilu Road, Jinan, 250012, Shandong, China, wm198817@163.com.
Meng
M
Wang
Zhi-Ping
ZP
Wang
Meng
M
Zhang
Zhong-Tang
ZT
Zhao
D000328:Adult; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007492:Iran / Q000453:epidemiology; D008431:Maternal-Fetal Exchange; D009436:Neural Tube Defects / Q000453:epidemiology*; D011247:Pregnancy; D012307:Risk Factors; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014481:United States / Q000453:epidemiology
D014028:Tobacco Smoke Pollution