Maternal smoking during late pregnancy and offspring smoking behaviour

Elevated risk of nicotine dependence among sib-pairs discordant for maternal smoking during pregnancy: evidence from a 40-year longitudinal study

BACKGROUND

Compelling evidence links maternal smoking during pregnancy with elevated risk of nicotine dependence among the offspring. However, no study to date has examined the maternal smoking during pregnancy-nicotine dependence link among sibling-pairs discordant for maternal smoking during pregnancy. We tested two hypotheses that, if supported, suggest that the maternal smoking during pregnancy-nicotine dependence link may be physiologically mediated.

METHODS

Study participants were adult offspring of women enrolled in the Providence and Boston sites of the Collaborative Perinatal Project (1959-1966). Approximately 10% of these adult offspring (average age: 39.6 years) were enrolled in the New England Family Study (n = 1,783), a follow-up study that oversampled families with multiple siblings. Logistic regression models predicting maternal smoking during pregnancy risk on various prospectively collected smoking and marijuana use outcomes, including nicotine dependence, were fit using models that allowed between-mother effects of maternal smoking during pregnancy exposure to differ from within-mother effects. In the absence of significant effect heterogeneity, we calculated a combined estimate.

RESULTS

Maternal smoking during pregnancy predicted progression from weekly smoking to nicotine dependence (odds ratio = 1.4 [95% confidence interval = 1.2, 1.8]), but not weekly smoking or progression to marijuana dependence.

CONCLUSIONS

Current evidence from sibling-pairs discordant for maternal smoking during pregnancy is consistent with previous reports of a dose-response association between maternal smoking during pregnancy and nicotine dependence, as well as of up-regulation of nicotine receptors among animals exposed to maternal smoking during pregnancy. Together, they provide support for the existence of a physiologically mediated link between maternal smoking during pregnancy and nicotine dependence.

Partner smoking and maternal cotinine during pregnancy: implications for negative control methods

BACKGROUND

Comparison of the associations of maternal and mother's partner smoking with offspring outcomes is, in theory, a useful method for assessing whether there may be an intrauterine effect of tobacco exposure on these outcomes. However, this approach assumes that the effects of passive smoking from exposure to partner smoking during pregnancy are minimal. We evaluated this assumption using a biochemical measure of tobacco exposure in pregnant women.

METHODS

Cotinine levels taken during the first trimester of pregnancy were measured in a sample of 3928 women from the Avon Longitudinal Study of Parents and Children. Median cotinine values were compared across categories of smoking heaviness (cigarettes per day) of the women during the first trimester and in non-smoking women by the smoking heaviness of their partner.

RESULTS

Cotinine levels were substantially higher in women who smoked compared to non-smokers (range of medians across smoking heaviness categories: 900-5362 ng/ml versus 20 ng/ml, interquartile range (IQR) (0-63) for non-smokers). In contrast, cotinine levels in non-smoking women were only very weakly related to partner smoking status (range of medians in women with smoking partners: 34-69 ng/ml versus 12 ng/ml, IQR (0-48) in women with non-smoking partners).

CONCLUSIONS

Levels of tobacco exposure from partner smoking, as assessed by cotinine, were low in non-smoking pregnant women. This suggests that using mother's partner's smoking as a negative control for investigating intrauterine effects is valid.

In-utero exposure to maternal smoking is not linked to tobacco use in adulthood after controlling for genetic and family influences: a Swedish sibling study

Previous studies have linked maternal smoking during pregnancy with regular tobacco use in offspring, but findings are not consistent and confounding from genetic and environmental factors have not fully been taken into account. A comparison between siblings discordant for prenatal smoking exposure adjusts for confounding by shared familial (i.e., genetic and environmental) factors. We investigated the association between prenatal exposure to maternal smoking during pregnancy and the risk of regular smoking or snus (Swedish moist smokeless tobacco) use in young adult offspring, using a population based matched cohort study. The cohort consisted of 1,538 randomly sampled same-sex sibling pairs, discordant for maternal smoking during pregnancy, 19-27 years old, participating in a survey conducted in Sweden 2010-2011. Lifetime and current history of tobacco use was self-reported in the survey, and information about maternal smoking during pregnancy was retrieved from the Medical Birth Register. Conditional logistic regression and stratified Cox proportional hazards regression were used to calculate odds ratios, hazard ratios, and corresponding 95% confidence intervals. Analyses of exposure-discordant siblings did not reveal significant associations between prenatal exposure to maternal smoking and lifetime or current daily tobacco use, intensity of use, or time to onset of daily tobacco use. These findings suggest that the previously reported higher risks of tobacco use in offspring of mothers who smoked during pregnancy, compared with offspring of non-smoking mothers, were likely due to confounding from genetic or environmental factors.

Is the intergenerational transmission of smoking from mother to child mediated by children's behavior problems?

INTRODUCTION

A previous paper used latent class analysis to assign individuals to 1 of 4 adolescent/young adult smoking trajectory classes and then established an association between maternal smoking before, during, and after pregnancy and these classes. In this paper, we examine one possible pathway for this relationship: that maternal smoking during pregnancy may set off a behavioral trajectory which increases the likelihood of problem behaviors generally, of which smoking is one manifestation.

METHODS

We used the Behavior Problems Index measure from age 8 through age 12 as a potential mediator. We used a path analysis modeling approach within a multinomial logistic regression (using Mplus) to estimate direct and indirect effects (via behavioral problems) between maternal smoking pattern and child trajectory class.

RESULTS

We found small but statistically significant indirect effects via behavioral problems from maternal smoking to child smoking trajectory for membership in all 3 smoking classes, relative to the nonsmoking trajectory, indicating partial mediation. Mediated effects were associated with maternal smoking after pregnancy, no statistically significant mediated effects were found for smoking before or during pregnancy.

CONCLUSIONS

The results provided no evidence that the effects of maternal smoking during pregnancy on child smoking trajectory are mediated by problem behavior. Effects from smoking after birth to child smoking trajectory appear to be partially mediated by problem behavior, supporting a behavioral rather than physiological effect of smoking during pregnancy but not ruling out more complex physiological pathways.

Does mother's smoking influence girls' smoking more than boys' smoking? A 20-year review of the literature using a sex- and gender-based analysis

A systematic literature review was conducted to examine whether mother's smoking influences girls' smoking more than boys' smoking. Fifty-seven studies, published between 1989 and 2009, were analyzed using a sex and gender lens. Results indicate that mother's prenatal and postnatal smoking influences girls' smoking more than boys' smoking. Despite evidence that sex and gender are important determinants of smoking among adolescents when examined in relation to mother's smoking, the theoretical understanding of why girls are more likely to smoke if prenatally and postnatally exposed to mother's smoking remains unclear. Implications for future research are discussed.

Prenatal exposure to maternal cigarette smoking and the adolescent cerebral cortex

Smoking during pregnancy is associated with long-term consequences on offspring behavior. We measured thickness of the cerebral cortex using magnetic resonance images obtained in 155 adolescents exposed in utero to maternal smoking and compared them with 159 non-exposed subjects matched by maternal education. Orbitofrontal, middle frontal, and parahippocampal cortices were thinner in exposed, as compared with non-exposed, individuals; these differences were more pronounced in female adolescents. In exposed females, the thickness of the orbitofrontal cortex correlated negatively with a self-rated assessment of caring, one of the components of a model of positive youth development. These findings provide evidence of the long-term impact of prenatal environment on a neural substrate of cognition and social behavior.

Bedingungsfaktoren eines frühen Erstkonsumalters von Tabak

Zusammenfassung. Bedingungsfaktoren eines frühzeitigen Beginns des Tabakkonsums, der als einer der besten Prädiktoren einer späteren Tabakabhängigkeit gilt, sollen überprüft und auf ihren Zusammenhang hin untersucht werden. In einer Längsschnittstudie an einer Geburtskohorte von 384 Risikokindern wurden das psychosoziale Risiko, das mütterliche Rauchen in der Schwangerschaft, der elterliche Tabak- und Alkoholkonsum sowie externale Verhaltensauffälligkeiten von Geburt bis zum Jugendalter erhoben. Mit 15 Jahren wurde das Alter beim ersten Tabakkonsum erfragt und mittels Überlebenszeitanalysen vorhergesagt. Jugendliche, die früh Zigaretten probierten, kamen eher aus Familien mit einer hohen psychosozialen Belastung, wobei dieser Einfluss über mehr externale Verhaltensauffälligkeiten vermittelt wurde. Ein starker täglicher Tabak- sowie ein riskanter Alkoholkonsum der Eltern erwiesen sich ebenfalls als Risikofaktoren für einen frühzeitigen Rauchbeginn der Kinder. Das elterliche Rauchen fungierte als Mediator für den Einfluss des mütterlichen Rauchens in der Schwangerschaft sowie der psychosozialen Belastung. Ein frühes Einstiegsalter in den Tabakkonsum kann als Folge genereller Risikofaktoren für die Entwicklung von Verhaltens- und Suchtproblemen interpretiert werden.