Does the Trimester of Smoking Matter in the Association between Prenatal Smoking and the Risk of Early Childhood Caries?

Abstract

<b><i>Introduction:</i></b> Development of the primary tooth bud commences at the end of the 5th week of gestation, with mineralization starting at about the 13th week and continuing throughout pregnancy to the end of the first year of life. During this critical period, exposure to maternal lifestyle factors, specifically, prenatal smoking can negatively affect the quality (i.e., tooth calcification and mineralization) and timing of tooth eruption. <b><i>Methods:</i></b> This study evaluated the association between the trimester of smoking and offspring caries experience at 3 time points (31, 43, and 61 months) by analyzing data from 1,429 mother-offspring participants in the 1991/92 Avon Longitudinal Study of Parents and Children, conducted in Bristol, England. Prenatal smoking in the first, second, and third trimesters were self-reported during pregnancy while offspring caries experience was determined by clinical oral examinations. Adjusted for confounders, log-binomial regression estimated the risk ratio (RR) and 95% confidence interval (CI) of the association between trimester of smoking and the risk of offspring caries. <b><i>Results:</i></b> Twenty percent smoked in the first trimester of their pregnancy, 15% in the second, and 17% in the third. Forty-six percent of children whose mothers smoked during pregnancy had caries experience (i.e., dmft ≥1) with a mean dmft count of 1.58, versus children whose mothers did not smoke during pregnancy (33% of whom had dmft ≥1 with a mean dmft count of 0.33). Smoking in the first, second, and third trimesters were independently associated with a higher adjusted RR (95% CI) of caries experience at 61 months, i.e., 1.16 (0.93–1.43), 1.11 (0.75–1.65), and 1.60 (1.09–2.32), respectively. <b><i>Conclusions:</i></b> Within the limitations of covariates adjusted for, with the caveat that residual confounding and bias from unmeasured covariates are likely present, our findings suggest that smoking during pregnancy may be harmful to the oral health of the offspring irrespective of the trimester during which the smoking occurred. Nevertheless, these results should be interpreted cautiously because the findings might not generalize broadly.

Correlation Between Maternal Smoking During Pregnancy and Dental Caries in Children: A Systematic Review and Meta-Analysis

“…The remaining 29 full-text articles were further evaluated according to eligibility criteria. Ultimately, 11 studies were included in our qualitative synthesis (Figure 1) [13][14][15][16][17][18][19][20][21][22][23]. Of these, 9 studies were included in the meta-analysis [14][15][16][17][19][20][21][22][23].…”

“…Of these, 9 studies were included in the meta-analysis [14][15][16][17][19][20][21][22][23]. Two articles [Akinkugbe [13] and Julihn et al [18]] were excluded because their data sources overlapped with the other articles, and we selected the articles [Akinkugbe et al [14] and Julihn et al [19]] with larger sample size or more complete data.…”

“…Among the included studies, six were cross-sectional studies [15,17,[19][20][21][22] and five were longitudinal studies [13,14,16,18,23]. For the region, six studies came from Europe [13][14][15][18][19][20]; three studies were conducted in Asia [21][22][23]; one was from the United States [17]; and one was carried out in Australia [16]. In terms of exposure assessment, most studies using the self-reported information by pregnant women.…”

“…The adverse effects of prenatal smoking on the health of offspring and the prevalence of childhood dental caries have led to hypothesis about a possible cause-and-effect relationship between them. Recently, although an increasing number of studies focused on the association between maternal smoking during pregnancy and childhood caries, their conclusions were not consistent [13][14][15][16][17][18][19][20][21][22][23]. Some studies suggested prenatal smoking could increase the risk of developing dental caries in children [13, 14, 16-19, 21, 22], while others did not observe any association between them [15,20,23].…”

“…Recently, although an increasing number of studies focused on the association between maternal smoking during pregnancy and childhood caries, their conclusions were not consistent [ 13 – 23 ]. Some studies suggested prenatal smoking could increase the risk of developing dental caries in children [ 13 , 14 , 16 – 19 , 21 , 22 ], while others did not observe any association between them [ 15 , 20 , 23 ]. These completely opposite results may be caused by various possible confounders because existing evidences suggest multiple factors like socioeconomic status, involuntary smoking, breastfeeding and its duration, maternal educational level and mode of delivery will affect the development of dental caries in children [ 19 , 24 – 28 ].…”