The Influence of Prenatal Exposure to Tobacco Smoke on Neonatal Body Proportions

The objective of this study was to determine neonatal anthropometric indices such as: birth weight, crown-heel length, head and chest circumference and ponderal index , in relation to the maternal smoker status (active and passive smoking). The study included 147 neonates born in 2003-2004 at the Princess Anna Mazowiecka University Hospital in Warsaw admitted to the Neonatal and Intensive Care Department of Warsaw Medical University. Neonates were assigned to one of three groups: babies of mothers who were active smokers, passive smokers and non-smokers based on a questionnaire concerning exposure to tobacco smoke and on the concentration of cotinine in maternal urine. The babies of mothers who were active smokers were born with lower birth weight (p=0.033), lower crown-heel length (p=0.026), lower head circumference (p=0.002) and lower chest circumference (p=0.021) significantly more often than babies of non-smoker mothers. Babies whose mothers were active smokers had an increased risk of lower head circumference or 3, 9 (1, 4-10, 7, CI 95%), and an increased risk of lower chest circumference OR 4, 0 (1, 5-10, 9, CI 95%). The babies of mothers who were passive smokers also had lower anthropometric indices, but the differences were not statistically significant. No effect on ponderal index was observed among the neonates whose mothers were active and passive smokers. Smoking during pregnancy causes symmetrical restriction of intrauterine growth.