Objectives To examine the association between early-life smoking exposure and later risk of inflammatory bowel disease (IBD) Methods We followed 115,663 participants from the Norwegian Mother, Father and Child (MoBa) and All Babies in Southeast Sweden (ABIS) cohorts from birth (1997-2009) through 2021. IBD was identified through national patient registers. Validated questionnaire data defined maternal smoking during pregnancy, maternal environmental tobacco smoke (ETS) exposure during pregnancy, and child ETS exposure by age 12 and 36 months. Cox regression was used to estimate adjusted hazard ratios (aHRs) for sex, maternal age, education level, parental IBD and origin. Cohort-specific estimates were pooled using a random-effects model Results During 1,987,430 person-years of follow-up, 444 participants developed IBD (ABIS, n=112; MoBa, n=332). Any vs. no maternal smoking during pregnancy yielded a pooled aHR of 1.30 (95%CI=0.97–1.74) for offspring IBD. Higher level of maternal smoking during pregnancy (compared to no smoking, average ≥6 cigarettes/day: pooled aHR=1.60 [95%CI 1.08–2.38]) was associated with offspring IBD, whereas a lower smoking level was not (average 1–5 cigarettes/day: pooled aHR=1.09 [95%CI=0.73–1.64]). Child ETS exposure in the first year of life was associated with later IBD (any vs. no ETS, pooled aHR=1.32 [95%CI=1.03–1.69]). Estimates observed for child ETS exposure by 36 months were similar but not statistically significant Conclusions In this prospective Scandinavian cohort study, children exposed to higher levels of maternal smoking during pregnancy or ETS during the first year of life were at increased risk of later IBD.

中文翻译：

---

儿童早期接触烟草烟雾和以后患炎症性肠病的风险：一项斯堪的纳维亚出生队列研究

目的 研究早期吸烟暴露与日后炎症性肠病 (IBD) 风险之间的关系 方法 我们对来自挪威母亲、父亲和儿童 (MoBa) 和瑞典东南部所有婴儿 (ABIS) 队列的 115,663 名参与者从出生起进行了跟踪调查（ 1997 年至 2009 年）至 2021 年。 IBD 通过国家患者登记册进行识别。经过验证的问卷数据定义了母亲在怀孕期间吸烟的情况、母亲在怀孕期间接触环境烟草烟雾 (ETS) 的情况，以及儿童在 12 个月和 36 个月时接触 ETS 的情况。 Cox 回归用于估计性别、产妇年龄、教育水平、父母 IBD 和出身的调整后风险比 (aHR)。使用随机效应模型汇总特定队列的估计结果 结果 在 1,987,430 人年的随访期间，444 名参与者患上了 IBD（ABIS，n=112；MoBa，n=332）。母亲在怀孕期间吸烟与不吸烟相比，后代 IBD 的汇总 aHR 为 1.30 (95% CI=0.97–1.74)。母亲在怀孕期间吸烟水平较高（与不吸烟相比，平均 ≥6 支/天：汇总 aHR=1.60 [95%CI 1.08–2.38]）与后代 IBD 相关，而较低的吸烟水平则与后代 IBD 无关（平均 1–每天 5 支香烟：汇总 aHR=1.09 [95%CI=0.73–1.64]）。儿童第一年接触 ETS 与后来的 IBD 相关（有 ETS 与无 ETS，汇总 aHR=1.32 [95%CI=1.03–1.69]）。 36 个月时观察到的儿童 ETS 暴露估计值相似，但不具有统计显着性 结论 在这项前瞻性斯堪的纳维亚队列研究中，在怀孕期间暴露于较高水平的母亲吸烟或在生命第一年期间暴露于较高水平的 ETS 的儿童日后患 IBD 的风险增加。