Fetal exposure to tobacco: nicotine and cotinine concentration in amniotic fluid and maternal saliva

AbstractObjective: Fetal exposure to tobacco constituents is a risk factor for negative birth outcomes. We aimed to determine the relationships between nicotine and cotinineconcentrations in amniotic fluidand maternal saliva.Methods: As part of a therapeutic trial, 42 pregnant smokers agreed to sample amniotic fluid(8 samples from amniocentesis, 34 at birth). Their smoking characteristics were collected along with the newborns’ birth outcomes.Results: The median concentrations [IQR] in amniotic fluidand saliva were 11 [7–31] and 38 [7–174] μg/L for nicotine and 72 [22–123] μg/L and 55 [17–109] μg/L for cotinine, respectively. Multivariate models showed that saliva cotinineconcentration predicted amniotic fluidnicotine and cotinineconcentrations (R2 = 0.398, p < 0.0001 and R2 = 0.708, p < 0.0001 respectively). Amniotic fluidnicotine or cotinineconcentration was not associated with birth weight. In multivariate analysis, the time elapsed since the last cigarette was the only variable associated wit...