Purpose: Prenatal tobacco smoke exposure may be associated with low maternal folate levels that increase the risk of adverse infant and child health outcomes by reducing folate availability during fetal development.
Methods: Using data from the Health Outcomes and Measures of the Environment Study, we examined the relationship between secondhand or active tobacco smoke exposure and whole blood folate concentrations in pregnant women from Cincinnati, Ohio (n = 362) at approximately 16-week gestation. We used multivariable linear regression to examine the association between continuous or categorical serum cotinine levels and whole blood folate levels, adjusting for sociodemographic, dietary, and perinatal variables.
Results: After adjustment for potential confounders, an interquartile range increases in serum cotinine concentration (0.012-0.224 ng/mL) was suggestively associated with decreased whole blood folate levels (β, -23 nmol/L; 95% confidence interval (CI), -49, 3; P value = .08). Compared with unexposed women, reductions in mean whole blood folate were observed among active smokers (β, -94, 95% CI, 195, 6 nmol/L; P value = .40); smaller reductions were observed among women with secondhand exposure (β, 26; CI, 84, 32 nmol/L; P value = .07).
Conclusions: Consistent with prior studies, active smoking was associated with reduced whole blood folate levels among these pregnant women. Secondhand tobacco smoke exposures were associated with small and imprecise reductions in whole blood folate levels.
Keywords: Epidemiology; Folic acid; Pregnancy; Smoking; Tobacco smoke pollution.
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