Combined Effects of Cigarette Smoking and Alcohol Consumption on Perinatal Outcome

Abstract

Background: An increase in various congenital abnormalities associated with cigarette smoking and the use of alcohol during pregnancy has been reported in many studies. These exposures also increase the risk of pregnancy complications such as abruptio placentae, unexplained stillbirth, preterm labor and intrauterine growth restriction. However, very few studies have addressed the combined effect of smoking and drinking on pregnancy outcomes. Methods: In this review, the adverse effects of smoking or drinking on pregnancy were obtained from publications in which both substances were addressed in the same study population. A special effort was made to find studies in which the combined effect of these substances was investigated. Results: Preterm labor occurred more frequently in women who drank and smoked during pregnancy. This increased odds ratio was more than the sum of the effects of either smoking or drinking, indicating that the use of both substances by the same woman has a synergistic effect that increases the risk of preterm labor. This synergistic effect was also found for low birth weight and growth restriction. Conclusions: As most of the women who drink during pregnancy also smoke cigarettes, attention should be given to the prevention or reduced use of both substances during pregnancy.

Prenatal alcohol exposure, blood alcohol concentrations and alcohol elimination rates for the mother, fetus and newborn

“…32 Smoking is a potent vasoconstrictor of the maternal vasculature, placenta and umbilical cord, which may modify dispersion rates of alcohol into the fetal compartment. Ethanol is also a potent vasoconstrictor and combined exposure likely results in long time windows of constriction.…”

Prevalence of smoking during pregnancy in the Republic of the Congo: Maternal smoking is associated with increased risk of prenatal alcohol exposure

“…The statistical modeling of adverse outcomes from a comprehensive review of combined exposure supports the conclusion that the combined exposure of prenatal smoking and alcohol use are not additive, but rather multiplicative, for many adverse outcomes (Odendaal et al, 2009). These findings support the need for widespread comprehensive public health intervention efforts to reduce maternal smoking and alcohol use before and during pregnancy, with an emphasis on efforts to reduce either or both of these behaviors across the childbearing years.…”

“…This is equivalent to one cigarette per day. Though this seems like a small amount of daily exposure, prolonged exposure to low levels of cigarette use still puts the pregnancy at increased risk for adverse birth outcomes, especially for women who drink alcohol during pregnancy (Odendaal et al, 2009). …”

“…Over the course of the 40 weeks of pregnancy, the estimated prenatal alcohol exposure difference was 266 more drinks and 80 more binge episodes (four or more drinks at one time) for the average woman who smoked. This comorbid exposure has important health consequences, especially for the fetus and child, since smoking is also associated with increased risk for adverse outcomes when accompanied by prenatal alcohol exposure (Odendaal, Steyn, Elliot, & Burd, 2009). Note.…”

“…Nine smokers (5.6 %) made up the "At Risk" drinking group and each smoked an average of 1.11 (sd = 0.33) cigarettes per day (Table 4). The "High Risk" group consisted of 151 smokers (87%) who reported using 1.13 (sd = 0.41) cigarettes per day (Table 4); these women are likely at an increased risk for a wide range of adverse outcomes (Odendaal et al, 2009). …”