Maternal smoking during pregnancy and school performance at age 15.

Department of Medical Epidemiology and Biostatistics, Karolinska Institutet, SE-171 77 Stockholm, Sweden.
Epidemiology (Impact Factor: 6.18). 10/2006; 17(5):524-30. DOI: 10.1097/
Source: PubMed

ABSTRACT Smoking during pregnancy has been suggested to have long-term consequences for neuropsychologic development in the offspring, including behavioral problems, attention deficit disorders, and antisocial behavior. Also, findings from several studies indicate an association with impaired cognitive function in the children.
In a population-based Swedish cohort study, we examined possible associations between maternal smoking in pregnancy and educational achievement in the offspring at age 15 years among more than 400,000 male and female students born 1983 through 1987. Generalized estimating equation models were used to evaluate associations of maternal smoking, other maternal characteristics, and birth characteristics with school performance. Odds ratios (ORs) were used as a measure of risk.
In a model adjusted for maternal characteristics, maternal smoking compared with no tobacco use during pregnancy was associated with an increased risk of poor scholastic achievement: for 1-9 cigarettes per day, the OR was 1.59 (95% confidence interval = 1.59-1.63) and for 10 or more cigarettes per day, the OR was 1.92 (1.86-1.98). These risks remained unchanged when we also adjusted for smoking-related pregnancy outcomes such as fetal growth restriction and preterm birth. However, if the mother had smoked in her first pregnancy, but not in her second pregnancy, the younger sibling was also at increased risk of poor school performance.
Observed associations between maternal smoking during pregnancy and poor cognitive performance in the offspring might not be causal. We suggest that associations reported in earlier studies may instead reflect the influence of unmeasured characteristics that differ between smokers and nonsmokers.

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    ABSTRACT: Background: Maternal smoking during pregnancy (MSDP) is associated with multiple adverse childhood outcomes including externalizing behaviors. However, the association between MSDP and internalizing (anxiety and depressive) behaviors in offspring has received less investigation. We aimed to assess the association between MSDP and childhood internalizing (anxiety and depressive) behaviors in a very large, well-characterized cohort study. Methods: We assessed the association between MSDP and internalizing behaviors in offspring utilizing information drawn from 90,040 mother-child pairs enrolled in the Norwegian Mother and Child Cohort Study. Mothers reported smoking information, including status and frequency of smoking, twice during pregnancy. Mothers also reported their child's internalizing behaviors at 18 months, 36 months, and 5 years. Associations between MSDP and childhood internalizing behaviors, including dose-response and timing of smoking in pregnancy, were assessed at each time point. Results: MSDP was associated with increased internalizing behaviors when offspring were aged 18 months (B = 0.11, P <0.001) and 36 months (B = 0.06, P <0.01), adjusting for numerous potential confounders. Higher rates of smoking (e.g., >20 cigarettes per day) were associated with higher levels of internalizing behaviors. Maternal smoking during early pregnancy appeared to be the critical period for exposure. Conclusions: We found evidence supporting a potential role for MSDP in increasing internalizing (anxiety and depressive) behaviors in offspring. We also found evidence supportive of a possible causal relationship, including dose-dependency and support for a predominant role of early pregnancy exposure. Further investigation utilizing genetically informed designs are warranted to assess this association.
    BMC Medicine 02/2015; 13(1). DOI:10.1186/s12916-014-0257-4 · 7.28 Impact Factor
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    ABSTRACT: Maternal smoking during pregnancy (SDP) has been associated with several psychiatric outcomes in the offspring; studies have questioned whether the associations are causal, however. We analyzed all children born in Sweden between 1983 and 2009 to investigate the effect of SDP on multiple indicators of adverse outcomes in three areas: pregnancy outcomes (birth weight, preterm birth and being born small for gestational age), long-term cognitive abilities (low academic achievement and general cognitive ability) and externalizing behaviors (criminal conviction, violent criminal conviction and drug misuse). SDP was associated with all outcomes. Within-family analyses of the pregnancy outcomes were consistent with a causal interpretation as the associations persisted when siblings discordant for SDP were compared. For the cognitive and externalizing outcomes, the results were not consistent with causal effects; when comparing differentially exposed siblings none of the associations remained significant. In quantitative genetic models genetic factors explained the majority of the associations between SDP and cognitive and externalizing outcomes. The results suggest that the associations between SDP in mothers and cognition and externalizing behaviors in their offspring is primarily due to genetic effects that influence the behaviors in both generations.
    Behavior Genetics 09/2014; 44(5). DOI:10.1007/s10519-014-9668-4 · 2.84 Impact Factor
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    ABSTRACT: Maternal smoking during pregnancy is one of the main causes of pregnancy complications and is correlated with poorer outcomes com-pared to pregnancy without smoking. Maternal smoking is associated with a statistically sig-nificant increase in the risks of placental abruption, placenta praevia, ectopic pregnancy and preterm pre-labor rupture of membranes. In addition, maternal smoking during preg-nancy correlated with higher rates of low birth weight, perinatal mortality, and premature birth, as well as complications in respiratory, cardiovascular and nervous systems in child-hood. Active and passive smoking of pregnant mothers seems to be one of the causative agents for these and other negative effects on both mothers and their infants. Physicians should clarify these hazardous effects to preg-nant women and strongly advise them to quit smoking as soon as possible. Women who con-tinue to smoke during pregnancy should be considered a high-risk pregnancy.
    02/2012; 2(1). DOI:10.4081/ts.2012.e1


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May 20, 2014