Does maternal smoking during pregnancy cause childhood overweight?

Abstract

The objective of this study was to examine a possible association between maternal smoking in pregnancy and childhood overweight. From a population-based cohort of 5722 women from Trondheim, Bergen (Norway) and Uppsala (Sweden) enrolled in early pregnancy during 1986-92, a random sample of 482 women was selected for participation. They were followed up throughout pregnancy, and their children from birth until 5 years of age. Data on maternal smoking and diet, socio-economic determinants and breast feeding were recorded prospectively. During pregnancy and childhood, anthropometric measures were also recorded. Maternal smoking status was based on reported number of cigarettes smoked in week 17 of pregnancy. Child overweight was defined by body mass index (BMI) and sum of skinfold thickness (SFT) >or= 85th percentile at 5 years of age. Children of mothers who smoked in pregnancy had increased risk of overweight at 5 years of age (RR 2.5, 95% CI 1.5, 4.2 for BMI; and RR 1.8, 95% CI 1.1, 3.0 for SFT). Adjusting for maternal diet, breast feeding, maternal obesity and socio-economic status did not suggest confounding. However, adjustment for birthweight increased the observed risk. A linear increase in BMI and SFT was observed with increasing number of cigarettes smoked. In conclusion, smoking during pregnancy may be a risk factor for development of childhood overweight. This study may support the hypothesis of 'fetal origin of adult disease', but the risk of overweight associated with smoking during pregnancy was independent of intrauterine growth retardation, and may thus be attributed to specific effects of cigarette smoke.

Maternal smoking during pregnancy and child overweight: systematic review and meta-analysis

“…In one study, adjustment for breastfeeding substantially strengthened the risk of overweight associated with maternal smoking. 27 The pooled estimate from the unadjusted odds ratios (OR 1.52, 95% CI: 1.36, 1.69, P for heterogeneity o0.001, I 2 ¼ 67, 45, 81%) was similar to the adjusted estimate.…”

“…Based on our meta-analysis, children whose mothers smoked during pregnancy were at elevated risk for overweight (pooled adjusted odds ratio (OR) 1.50, 95% CI: 1.36, 1.65, P for heterogeneity ¼ 0.02, I 2 ¼ 49%, 95% CI: 8, 71%) compared with children whose mothers did not smoke during pregnancy (Figure 2). The study by Wideroe et al 27 had the largest effect on the pooled estimate, but excluding that study only slightly influenced the pooled odds ratio (OR 1.44, 95% CI: 1.33, 1.56, P for heterogeneity ¼ 0.13, I 2 ¼ 30%, 95% CI: 0, 62%). Excluding studies in which mothers were asked about prenatal smoking at the same time outcomes were assessed [23][24][25] Mothers who smoked during pregnancy tended to be substantially different from nonsmokers in ways that also predict child obesity risk.…”

“…Prenatal smoking and child overweight Our literature review yielded 14 studies eligible for inclusion in the meta-analysis of smoking and overweight risk [14][15][16][17][18][19][20][21][22][23][24][25][26][27] ( Table 1). These studies included 84 563 children, and represent pregnancies that occurred from 1958 to 2002 in low and non-low income populations in Australia, North America, and Europe.…”

Fetal and neonatal exposure to nicotine in Wistar rats results in increased beta cell apoptosis at birth and postnatal endocrine and metabolic changes associated with type 2 diabetes

“…Recent epidemiological studies have shown that the offspring of women who smoke during pregnancy have an increased risk of developing obesity, hypertension and type 2 diabetes [1][2][3][4][5][6][7][8]. The mechanism(s) underlying these associations are unknown.…”

“…One such stress is maternal cigarette smoking. Recent epidemiological studies have shown a strong relationship between maternal smoking and subsequent obesity, hypertension and type 2 diabetes in the offspring [1][2][3][4][5][6][7][8]. Although many women report a desire to quit smoking while pregnant, nicotine dependence is a significant element of most patients' smoking behaviour [9].…”