Postgraduate Programme in Epidemiology, Universidade Federal de Pelotas, Brazil; Centro de Epidemiologia Ufpel Dr. Amilcar Gigante, R. Mal. Deodoro, 1160 - Centro, Pelotas, Brazil.
Postgraduate Programme in Epidemiology, Universidade Federal de Pelotas, Brazil.
Prev Med. 2022 Mar;156:106983. doi: 10.1016/j.ypmed.2022.106983. Epub 2022 Feb 9.
Maternal smoking during pregnancy causes several harmful effects, including deficits in the intelligence quotient (IQ), a measure associated with academic achievements and higher socioeconomic position. We aimed to measure the association between maternal smoking during pregnancy and offspring's IQ in two birth cohorts from Pelotas, Brazil. Data from the 1982 and 1993 birth cohorts were analyzed. Smoking during pregnancy was ascertained at the perinatal follow-up, and IQ was measured at 30 years (1982) and 18 years (1993). Simple and multiple linear regressions were used for crude and adjusted analysis. Mediation analysis was performed using birth weight and breastfeeding as possible mediators. Data analysis was conducted in 2020. There were 3611 and 4050 participants from the 1982 and 1993 cohorts, respectively. After adjustment for potential confounders, the inverse association between smoking during pregnancy and children's IQ remained significant in both cohorts. Offspring of mothers who smoked during pregnancy had an average of 1.32 less IQ points (95%CI: -2.23, -0.242) in the 1982 cohort, and an average of 1.66 less IQ points (95%CI: -2.42, -0.90) in the 1993 cohort. Neither cohort showed association with paternal smoking (negative controls) after adjustment. Breastfeeding's mediated effects accounted for 26.2% and 23.9% of the association in the 1982 and 1993 cohorts, respectively, while birth weight's accounted for 6.8% and 30.1%, respectively; indirect effects were not significant. The inverse association between maternal smoking and IQ and the lack of association with paternal smoking reinforces our findings of a negative association between exposure and outcome.
孕期母亲吸烟会导致多种有害影响，包括智商（IQ）缺陷，这是与学业成绩和更高社会经济地位相关的一个指标。我们旨在通过来自巴西佩洛塔斯的两个出生队列来衡量孕期母亲吸烟与子女 IQ 之间的关联。分析了 1982 年和 1993 年出生队列的数据。在围产期随访时确定了孕期吸烟情况，在 30 岁（1982 年）和 18 岁（1993 年）时测量了 IQ。使用简单和多元线性回归进行了粗分析和调整分析。使用出生体重和母乳喂养作为可能的中介进行了中介分析。数据分析于 2020 年进行。1982 年和 1993 年队列分别有 3611 名和 4050 名参与者。在调整了潜在混杂因素后，在两个队列中，孕期吸烟与儿童 IQ 呈负相关仍然具有统计学意义。孕期吸烟母亲的子女在 1982 年队列中平均 IQ 得分低 1.32 分（95%CI：-2.23，-0.242），在 1993 年队列中平均 IQ 得分低 1.66 分（95%CI：-2.42，-0.90）。在调整后，两个队列均与父亲吸烟（阴性对照）无关。母乳喂养的中介效应分别占 1982 年和 1993 年队列关联的 26.2%和 23.9%，而出生体重的分别占 6.8%和 30.1%；间接效应不显著。母亲吸烟与 IQ 呈负相关，与父亲吸烟无关，这进一步证实了我们的发现，即暴露与结果之间存在负相关。
