[Environmental tobacco smoke exposure in pregnancy and postpartum period]

Among available methods to estimate the exposure to tobacco smoke, cotinine, a major metabolite of nicotine is considered the most accurate marker. The aim of this study was to evaluate environmental tobacco smoke exposure in pregnancy and postpartum period. The cohort study was conducted in 2004 and 2006 in public maternity units in Lodz, Poland. The study population consisted of women between 32-36 weeks of pregnancy who have quit smoking within 2 months before pregnancy or no later than three months prior to participation in the study. Women were interviewed twice: during pregnancy and three months after delivery. Self-reported non-smoking status was verified using saliva cotinine level. Cotinine level in saliva sample was analyzed using Liquid Chromatography with Tandem Mass Spectrometry. We included into the analysis 62 women who, based on self-reported smoking status and saliva cotinine level were classified as non-smokers. There were no statistically significant differences in mean saliva cotinine level measured in pregnancy and postpartum period. Pregnant women who smoked more cigarettes per day before quitting smoking had significantly higher cotinine level comparing to women who smoked < or = 10 cigarettes per day (p = 0.03). Saliva cotinine level was significantly higher among women exposed to environmental tobacco smoke at home compared to non-exposed (p = 0.02).