A Meta-Analysis of Maternal Smoking during Pregnancy and Autism Spectrum Disorder Risk in Offspring.

Xuan Gong,Shiming Tang,Ying Wang,Gaohua Wang

doi:10.3390/ijerph120910418

Abstract

The association between maternal smoking during pregnancy and autism spectrum disorder (ASD) risk in offspring has been investigated in several studies, but the evidence is not conclusive. We, therefore, conducted this meta-analysis to explore whether an association exists between maternal smoking during pregnancy and ASD risk in offspring. We searched PubMed, Embase, Web of Science, and the Cochrane Library for studies of maternal smoking during pregnancy and ASD risk in offspring up to 10 June 2015. The random-effects model was used to combine results from individual studies. 15 observational studies (6 cohort studies and 9 case-control studies), with 17,890 ASD cases and 1,810,258 participants were included for analysis. The pooled odds ratio (OR) was 1.02 (95% confidence interval (CI): 0.93–1.13) comparing mothers who smoked during pregnancy with those who did not. Subgroup and sensitivity analysis suggested the overall result of this analysis was robust. Results from this meta-analysis indicate that maternal smoking during pregnancy is not associated with ASD risk in offspring. Further well-designed cohort studies are needed to confirm the present findings.

Highlights

Autism Spectrum Disorders (ASDs) are a group of heterogeneous neurodevelopmental conditions characterized by social and communication difficulties, and by restricted and repetitive interests and behaviors [1]
Women with lower socioeconomic status (SES) have a higher tendency to smoke during pregnancy compared with those with higher SES [33,34]; low parental SES is associated with an increased risk of ASD [35]
A third explanation is the transmission of genetic risk from mothers to their offspring, as ASD is highly genetic [4] and smoking during pregnancy is more likely to happen in women with a predisposition to mental health and behavioral problems [36]

Summary

Introduction

Autism Spectrum Disorders (ASDs) are a group of heterogeneous neurodevelopmental conditions characterized by social and communication difficulties, and by restricted and repetitive interests and behaviors [1]. The ASDs include autistic disorder, Asperger syndrome, atypical autism, and other or unspecified pervasive developmental disorders [2]. The identification of modifiable environmental risk factors is of great importance for the primary prevention of ASDs. Smoking during pregnancy may lead to numerous adverse outcomes in the offspring, such as low birth weight, placenta abruption, and sudden infant death syndrome [5]. Maternal smoking is a risk factor for several neurodevelopmental disorders, including attention-deficit, conduct disorder, and antisocial behavior [6]. Several studies have explored the relationship of maternal smoking during pregnancy and ASDs risk, but the results were inconclusive.

Methods

Results

Conclusion