Madley-Dowd Paul, Thomas Richard, Boyd Andy, Zammit Stanley, Heron Jon, Rai Dheeraj
Centre for Academic Mental Health, Population Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom.
National Institute for Health and Care Research (NIHR) Bristol Biomedical Research Centre, University Hospitals Bristol and Weston National Health Service (NHS) Foundation Trust and University of Bristol, Bristol, United Kingdom.
Front Psychiatry. 2024 Jun 25;15:1352077. doi: 10.3389/fpsyt.2024.1352077. eCollection 2024.
Observational studies have described associations of maternal smoking during pregnancy with intellectual disability (ID) in the exposed offspring. Whether these results reflect a causal effect or unmeasured confounding is still unclear.
Using a UK-based prospectively collected birth cohort (the Avon Longitudinal Study of Parents and Children) of 13,479 children born between 1991 and 1992, we assessed the relationship between maternal smoking at 18 weeks' gestation and offspring risk of ID, ascertained through multiple sources of linked information including primary care diagnoses and education records. Using confounder-adjusted logistic regression, we performed observational analyses and a negative control analysis that compared maternal with partner smoking in pregnancy under the assumption that if a causal effect were to exist, maternal effect estimates would be of greater magnitude than estimates for partner smoking if the two exposures suffer from comparable biases.
In observational analysis, we found an adjusted odds ratio for ID of 0.75 (95% CI = 0.49-1.13) for any maternal smoking and 0.97 (95% CI = 0.71-1.33) per 10-cigarette increase in number of cigarettes smoked per day. In negative control analysis, comparable effect estimates were found for any partner smoking (OR = 0.94; 95% CI = 0.63-1.40) and number of cigarettes smoked per day (OR = 0.94; 95% CI = 0.74-1.20).
The results are not consistent with a causal effect of maternal smoking during pregnancy on offspring ID.
观察性研究描述了孕期母亲吸烟与暴露后代智力残疾（ID）之间的关联。这些结果是否反映因果效应或未测量的混杂因素仍不清楚。
利用基于英国前瞻性收集的13479名1991年至1992年出生儿童的出生队列（埃文父母与儿童纵向研究），我们评估了妊娠18周时母亲吸烟与后代患ID风险之间的关系，通过包括初级保健诊断和教育记录在内的多个关联信息来源确定。使用混杂因素调整的逻辑回归，我们进行了观察性分析和阴性对照分析，在假设如果存在因果效应的情况下，比较孕期母亲吸烟与伴侣吸烟，前提是如果两种暴露存在可比偏差，母亲效应估计值的幅度将大于伴侣吸烟的估计值。
在观察性分析中，我们发现任何母亲吸烟的ID调整比值比为0.75（95%CI = 0.49 - 1.13），每天吸烟量每增加10支，调整比值比为0.97（95%CI = 0.71 - 1.33）。在阴性对照分析中，发现任何伴侣吸烟（OR = 0.94；95%CI = 0.63 - 1.40）和每天吸烟量（OR = 0.94；95%CI = 0.74 - 1.20）的效应估计值相当。
结果与孕期母亲吸烟对后代ID的因果效应不一致。
