Cotinine as an indicator of fetal exposure to active and passive smoking in pregnant women

Abstract

Introduction. Within 5 years, the number of pregnant smokers in Poland decreased by 5%. Still, 6% of pregnant women are active and 18% are passive smokers, and 5% smoke and drink alcohol. The study examined the levels of cotinine concentration in the blood of pregnant women and in the umbilical cord blood of their children in relation to the number of cigarettes smoked; the places and persons conducive to exposure of pregnant women to tobacco smoke were determined. Materials and Methods. The study included 123 women who have entered medical facilities for childbirth during physiological pregnancy, who filled out a questionnaire about their lifestyle. Moreover, venous and umbilical blood was collected from them and their newborns for cotinine evaluation. The nicotine marker was determined by the UPLC/MS/MS analytical method. Results. When examining the frequency of smoking and exposure to smoke, it was found that 38% of the respondents concealed their smoking status by giving false answers, as shown by the biochemical analysis of the presence of cotinine in the blood. A significant correlation was found between the cotinine levels of exposed and smoking mothers and their babies. Pregnant smokers were in the presence of smokers more often (p = 0.019). Moreover, it was found that the presence of women in the company of smokers who smoked more than 20 cigarettes/day resulted in a significant (p = 0.011) increase of cotinine in the umbilical blood in 31.5% of newborns, higher than the concentration in mothers. Conclusions. Protecting women from passive smoking requires extensive educational measures. The inclusion of cotinine level assessment in pregnant women in the program of the standard of perinatal examinations should be considered in order to protect children from diseases resulting from the effects of nicotine in the embryonic period.