Prenatal tobacco exposure is associated with some neurodevelopmental risks

Danrong Chen; Qing Niu; Shiping Liu; Wenchuan Shao; Yi Huang; Y. Xu; Yihan Li; Jiani Liu; Xu Wang; Haibo Yang (2023). The correlation between prenatal maternal active smoking and neurodevelopmental disorders in children: a systematic review and meta-analysis. BMC Public Health, 23.

Meta-analysis · N = 50,317 · prenatal exposure with child outcomes

Prenatal active smoking was associated with higher odds of the pooled neurodevelopmental outcomes and developmental coordination disorder; the Tourette-syndrome estimate was not significant.

Bearing on this claim: Meta-analysis supports associations with pooled neurodevelopmental outcomes while leaving causal interpretation qualified.

Yan He; Li-Hua Zhu; L. Hua; Fang-Fang Ke (2020). Maternal Smoking During Pregnancy and ADHD: Results From a Systematic Review and Meta-Analysis of Prospective Cohort Studies. Journal of Attention Disorders, 24:1637-1647.

Meta-analysis · N = 17,304 · prenatal exposure with child outcomes

Across twelve prospective cohorts, maternal smoking during pregnancy was associated with higher observed ADHD risk; the design does not by itself eliminate familial or genetic confounding.

Bearing on this claim: Prospective-cohort meta-analysis supports an observed ADHD association but does not eliminate familial or genetic confounding.

E. Haan; Kirsten Westmoreland; L. Schellhas; H. Sallis; Gemma M. J. Taylor; L. Zuccolo; M. Munafo (2021). Prenatal smoking, alcohol and caffeine exposure and offspring externalizing disorders: a systematic review and meta-analysis. Addiction, 117:2602-2613.

Meta-analysis · N = 1,011,546 · prenatal exposure with child outcomes

Conventional studies showed associations, but genetically sensitive designs did not support a clear causal prenatal-smoking-to-ADHD relationship.

Bearing on this claim: Genetically sensitive synthesis supports the scoped causal qualification by finding no clear causal smoking-to-ADHD relationship.

M. L. Correa; P. H. M. Soares; B. G. C. da Silva; F. Wehrmeister; B. Horta; A. Menezes (2021). Maternal smoking during pregnancy and intelligence quotient in offspring: a systematic review and meta-analysis. Neurotoxicology.

Meta-analysis · childhood through adulthood

Prenatal smoking was associated with a small adjusted IQ difference amid very high heterogeneity; the authors urged cautious interpretation.

Bearing on this claim: IQ meta-analysis supports a small adjusted association amid very high heterogeneity and explicit caution.

V. Knopik (2009). Maternal smoking during pregnancy and child outcomes: Real or spurious effect?. Developmental Neuropsychology, 34:1-36.

Review · prenatal exposure with child outcomes

The review described cognitive and behavioral associations but emphasized that environmental and genetic confounding prevented confident causal attribution.

Bearing on this claim: Review supports cognitive and behavioral associations while explaining why environmental and genetic confounding prevents general causal attribution.

C. Obel; J. Zhu; J. Olsen; Sanni Breining; Jiong Li; T. Gronborg; M. Gissler; M. Rutter (2016). The risk of attention deficit hyperactivity disorder in children exposed to maternal smoking during pregnancy - a re-examination using a sibling design. Journal of Child Psychology and Psychiatry, 57:532-537.

Longitudinal · N = 968,665 · prenatal exposure through childhood

The conventional ADHD association was nearly eliminated in sibling analysis, supporting familial or genetic confounding rather than a strong causal intrauterine effect.

Bearing on this claim: National sibling study supports the scoped ADHD qualification by nearly eliminating the conventional association after familial control.

Ondine S. von Ehrenstein; Xin Cui; Qi Yan; H. Aralis; B. Ritz (2020). Maternal Prenatal Smoking and Autism Spectrum Disorder in Offspring: a California Statewide Cohort and Sibling Study. American Journal of Epidemiology.

Longitudinal · N = 2,015,104 · prenatal exposure through childhood

Maternal smoking showed a small adjusted ASD association; heavy smoking had a larger estimate, while lighter-smoking associations were weaker and sibling estimates were imprecise.

Bearing on this claim: Statewide cohort and sibling study supports dose-sensitive ASD associations, with stronger heavy-smoking and weaker light-smoking estimates.

Lan Huang; Yan Wang; Li Zhang; Zhen Zheng; Tingting Zhu; Y. Qu; D. Mu (2018). Maternal Smoking and Attention-Deficit/Hyperactivity Disorder in Offspring: A Meta-analysis. Pediatrics, 141.

Meta-analysis · N = 2,998,059 · prenatal exposure through childhood

Prenatal smoking was associated with ADHD in a dose-graded pattern, but exposure measures varied and the meta-analysis did not resolve familial-confounding or causality questions.

Bearing on this claim: Large meta-analysis supports an observed dose-graded ADHD association while expressly leaving causality unresolved.

Kristin Gustavson; E. Ystrom; C. Stoltenberg; E. Susser; P. Suren; P. Magnus; G. Knudsen; G. Smith; K. Langley; M. Rutter; Heidi Aase; T. Reichborn-Kjennerud (2017). Smoking in Pregnancy and Child ADHD. Pediatrics, 139.

Longitudinal · prenatal exposure through childhood

Negative-control and sibling analyses did not support a causal intrauterine smoking-to-ADHD effect and instead indicated unmeasured familial confounding.

Bearing on this claim: Negative-control and sibling analyses support the causal-limit statement by indicating familial confounding rather than an intrauterine ADHD effect.