Assessment of urinary concentration of cotinine in Chinese pregnant women exposed to environmental tobacco smoke

Environmental tobacco smoke (ETS) is a well-known reason of many adverse health consequences in pregnant women. Exposure of ETS during pregnancy may increase the risk of some fetal diseases in pregnant women and/or birth defects in neonates. Many countries have implemented laws to control smoking and free of second hand smoke in all enclosed workplaces. In China, anti-smoking law was enforced in March 2010. We aimed to assess the exposure of pregnant women to cotinine after anti-smoking law was implemented in China. The urine samples were collected from 2,100 volunteers from Zhejiang Province, China and urinary concentration of cotinine was measured using gas chromatography and mass spectrometry. Cotinine was detected in 87 % of the pregnant women. The GM and 95th percentile concentration in pregnant women were 4.28 and 44.00 μg/L, respectively. Similarly, the GM and 95th concentration of cotinine were significantly higher in smoking group than in non-smoking group (P < 0.0001). Our results indicate that pregnant women in China are at the high risk of exposure ETS. Further attempts are required to make strategies to find out the sources of ETS exposure and prevent smoking at public places especially during pregnancy.