Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
Paediatr Perinat Epidemiol. 2010 Jan;24(1):79-87. doi: 10.1111/j.1365-3016.2009.01073.x.
Smoking during pregnancy has been linked to an increased risk of several adverse birth outcomes. Associations with deficits in cognitive development have also been suggested. It is unclear whether these associations are due to genetic and/or environmental confounding. In a population-based Swedish cohort study on 205,777 singleton males born to Nordic mothers between 1983 and 1988, we examined the association between maternal smoking during pregnancy and the risk of poor intellectual performance in young adult male offspring. In the cohort analyses, the risk of poor intellectual performance was increased in sons of smoking mothers compared with sons of non-smokers. Stratifying for maternal smoking habits across two pregnancies, there was an increased risk of poor intellectual performance for both sons if the mother was only smoking in the first pregnancy, but in neither son if the mother was only smoking in the second pregnancy. The effect of smoking during pregnancy on intellectual performance was not present when the association was evaluated within sibling pairs. Thus, the association between prenatal smoking exposure and offspring risk of low intellectual performance appears to be completely confounded by familial (genetic and early environmental) factors.
怀孕期间吸烟与多种不良出生结局的风险增加有关。也有研究表明，吸烟与认知发育缺陷有关。目前尚不清楚这些关联是否是由于遗传和/或环境混杂因素造成的。在一项针对 1983 年至 1988 年间出生于北欧母亲的 205777 名单胎男性的基于人群的瑞典队列研究中，我们研究了母亲怀孕期间吸烟与年轻男性后代智力表现不佳的风险之间的关系。在队列分析中，与不吸烟母亲的儿子相比，吸烟母亲的儿子智力表现不佳的风险增加。对两次妊娠期间母亲吸烟习惯进行分层，如果母亲仅在第一次妊娠中吸烟，则两个儿子智力表现不佳的风险均增加，但如果母亲仅在第二次妊娠中吸烟，则两个儿子均无此风险。当在兄弟姐妹对中评估关联时，怀孕期间吸烟对智力表现的影响并不存在。因此，产前吸烟暴露与后代智力表现低下风险之间的关联似乎完全受到家族（遗传和早期环境）因素的混杂。
