Population-Based Study of Smoking Behaviour throughout Pregnancy and Adverse Perinatal Outcomes

Abstract

There has been limited research addressing whether behavioural change in relation to smoking is maintained throughout pregnancy and the effect on perinatal outcomes. A cohort study addressed lifestyle behaviours of 907 women who booked for antenatal care and delivered in a large urban teaching hospital in 2010–2011. Adverse perinatal outcomes were compared for “non-smokers”, “ex-smokers” and “current smokers”. Of the 907 women, 270 (30%) reported smoking in the six months prior to pregnancy, and of those 160 (59%) had stopped smoking and 110 (41%) continued to smoke at the time of the first antenatal visit. There was virtually no change in smoking behaviour between the first antenatal visit and the third trimester of pregnancy. Factors associated with continuing to smoke included unplanned pregnancy (OR 1.9; 95% CI 1.3, 2.9), alcohol use (OR 3.4; 95% CI 2.1, 6.0) and previous illicit drug use (OR 3.6; 95% CI 2.1, 6.0). Ex-smokers had similar perinatal outcomes to non-smokers. Current smoking was associated with an average reduction in birth weight of 191g (95% CI −294, −88) and an increased incidence of intrauterine growth restriction (24% versus 13%, adjusted OR 1.39 (95% CI 1.06, 1.84). Public Health campaigns emphasise the health benefits of quitting smoking in pregnancy. The greatest success appears to be pre-pregnancy and during the first trimester where women are largely self-motivated to quit.

Consequences and Possible Predictors of Health-damaging Behaviors and Mental Health Problems in Pregnancy – A Review

“…Women who drank more than two alcoholic drinks per week or more than five alcoholic drinks per occasion (binge drinking) before they became pregnant, found it significantly more difficult to abstain entirely from drinking alcohol during pregnancy [55,60,65]. The same applied to pregnant women who had additionally smoked before or during pregnancy [55,[63][64][65][66]. Two of the studies found a correlation between continued maternal alcohol consumption and unplanned pregnancy [55,60]; it was not clear, however, whether nullipara or multipara found it more difficult to abstain from drinking alcohol [36].…”

“…Multipara were found to be a group at particular risk of continuing to smoke during pregnancy compared to women who were pregnant with their first child or women who had previously given birth to only one child [32, 35, 56-57, 65, 67]. In contrast to maternal nicotine consumption the consumption of low to moderate amounts of alcohol during pregnancy is a risk factor which was more likely to affect women with a higher socio-economic status and women who were older (aged > 30 years) [34,61,63,66]. Skagerstróm et al [36], who summarized the findings of 14 studies published between 2002 and 2009, did not come to a definitive conclusion with respect to the impact of the pregnant womanʼs social status on her prenatal consumption of alcohol.…”

The causal web of foetal alcohol spectrum disorders: a review and causal diagram

“…Proposed biologic mechanisms for the interaction between tobacco and alcohol include common effects on nutrient availability, oxidative stress and vasoconstriction of the placenta and umbilical cord, which can lead to hypoxia and prolonged uterine exposure to ethanol [5,66,67]. In addition to its interactive effect with PAE, prenatal smoking is independently associated with reduced foetal growth, low birthweight and cognitive and behavioural impairment [68][69][70][71][72][73][74][75]. Evidence suggests that the impact of smoking on decreased birth weight is up to three times greater than that of PAE [68,76].…”

“…Therefore, prenatal tobacco exposure can lead to characteristics that resemble FASD, even in the absence of alcohol exposure. Prenatal smoking is more common among mothers with an unplanned pregnancy, mothers with other forms of substance use, mothers who report prenatal stress, 1 3 younger mothers, and mothers of lower socioeconomic status (SES) [19,69,73,77].…”

Combined effects of AHR , CYP1A1 , and XRCC1 genotypes and prenatal maternal smoking on infant birth size: Biomarker assessment in the Hokkaido Study

“…Many of these compounds are carcinogenic, and their metabolites can form DNA adducts [3][4][5]. In previous studies, maternal smoking during pregnancy was associated with adverse pregnancy outcomes, i.e., miscarriage, stillbirth, and low birth weight [6][7][8].…”