Maternal smoking during pregnancy and offspring smoking initiation: assessing the role of intrauterine exposure

Addiction. 2014 Jun;109(6):1013-21. doi: 10.1111/add.12514. Epub 2014 Mar 17.


Aims: To assess whether associations between maternal smoking during pregnancy and offspring smoking initiation are due to intrauterine mechanisms.

Design: Comparison of associations of maternal and partner smoking behaviour during pregnancy with offspring smoking initiation using partner smoking as a negative control (n = 6484) and a Mendelian randomization analysis (n = 1020), using a genetic variant in the mothers as a proxy for smoking cessation during pregnancy.

Setting: A longitudinal birth cohort in South West England.

Participants: Participants of the Avon Longitudinal Study of Parents and Children (ALSPAC).

Measurements: Smoking status during pregnancy was self-reported by mother and partner in questionnaires administered at pregnancy. Latent classes of offspring smoking initiation (non-smokers, experimenters, late-onset regular smokers and early-onset regular smokers) were previously developed from questionnaires administered at 14-16 years. A genetic variant, rs1051730, was genotyped in the mothers.

Findings: Both mother and partner smoking were similarly positively associated with offspring smoking initiation classes, even after adjustment for confounders. Odds ratios (OR) [95% confidence interval (CI)] for class membership compared with non-smokers were: experimenters: mother OR = 1.33 (95% CI = 1.06, 1.67), partner OR = 1.28 (95% CI = 1.06, 1.55), late-onset regular smokers: mother OR = 1.80 (95% CI = 1.43, 2.26), partner OR = 1.86 (95% CI = 1.52, 2.28) and early-onset regular smokers: mother OR = 2.89 (95% CI = 2.12, 3.94), partner OR = 2.50 (95% CI = 1.85, 3.37). There was no clear evidence for a dose-response effect of either mother or partner smoking heaviness on class membership. Maternal rs1051730 genotype was not clearly associated with offspring smoking initiation class in pre-pregnancy smokers (P = 0.35).

Conclusion: The association between smoking during pregnancy and offspring smoking initiation does not appear to operate through intrauterine mechanisms.

Keywords: ALSPAC; Mendelian randomization; intrauterine; maternal smoking; negative control; offspring smoking; pregnancy; tobacco.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Adult
  • Cohort Studies
  • Cross-Sectional Studies
  • England
  • Female
  • Humans
  • Longitudinal Studies
  • Male
  • Odds Ratio
  • Pregnancy
  • Prenatal Exposure Delayed Effects*
  • Risk Assessment / statistics & numerical data
  • Risk Factors
  • Smoking / epidemiology*
  • Statistics as Topic
  • Surveys and Questionnaires
  • Tobacco Smoke Pollution / adverse effects*


  • Tobacco Smoke Pollution