Institute of Environmental Medicine, Karolinska Institutet, Box 210, SE-171 77 Stockholm, Sweden.
Am J Respir Crit Care Med. 2012 Nov 15;186(10):1037-43. doi: 10.1164/rccm.201203-0501OC. Epub 2012 Sep 5.
Although epidemiological studies suggest that exposure to maternal smoking during fetal and early life increases the risk of childhood wheezing and asthma, previous studies were not able to differentiate the effects of prenatal from postnatal exposure.
To assess the effect of exposure to maternal smoking only during pregnancy on wheeze and asthma among preschool-age children.
A pooled analysis was performed based on individual participant data from eight European birth cohorts. Cohort-specific effects of maternal smoking during pregnancy, but not during the first year, on wheeze and asthma at 4 to 6 years of age were estimated using logistic regression and then combined using a random effects model. Adjustments were made for sex, parental education, parental asthma, birth weight, and siblings.
Among the 21,600 children included in the analysis, 735 children (3.4%) were exposed to maternal smoking exclusively during pregnancy but not in the first year after birth. In the pooled analysis, maternal smoking only during pregnancy was associated with wheeze and asthma at 4 to 6 years of age, with adjusted odds ratios of 1.39 (95% confidence interval, 1.08-1.77) and 1.65 (95% confidence interval, 1.18-2.31), respectively. The likelihood to develop wheeze and asthma increased statistically significantly in a linear dose-dependent manner in relation to maternal daily cigarette consumption during the first trimester of pregnancy.
Maternal smoking during pregnancy appears to increase the risk of wheeze and asthma among children who are not exposed to maternal smoking after birth.
尽管流行病学研究表明，胎儿期和婴儿期接触母体吸烟会增加儿童喘息和哮喘的风险，但先前的研究无法区分产前和产后暴露的影响。
评估仅在怀孕期间接触母体吸烟对学龄前儿童喘息和哮喘的影响。
基于来自 8 个欧洲出生队列的个体参与者数据进行了汇总分析。使用逻辑回归估计妊娠期间母亲吸烟（但不包括出生后第一年）对 4 至 6 岁时喘息和哮喘的特定队列影响，然后使用随机效应模型进行合并。调整了性别、父母教育程度、父母哮喘、出生体重和兄弟姐妹等因素。
在分析中纳入的 21600 名儿童中，有 735 名（3.4%）儿童仅在怀孕期间暴露于母体吸烟，但在出生后第一年没有暴露。在汇总分析中，仅在怀孕期间接触母体吸烟与 4 至 6 岁时的喘息和哮喘有关，调整后的比值比分别为 1.39（95%置信区间，1.08-1.77）和 1.65（95%置信区间，1.18-2.31）。与妊娠早期母亲每日吸烟量呈线性剂量依赖性关系，发生喘息和哮喘的可能性呈统计学显著增加。
妊娠期间母亲吸烟似乎会增加未接触产后母亲吸烟的儿童喘息和哮喘的风险。
