Influence of maternal smoking behaviour and antioxidant vitamin concentrations on the birth weight of new born infants

An epidemiological study into the influence of cotinine validated maternal smoking and antioxidant vitamin concentrations on new born infants was carr ied out from 1992 to 1994 in the Department of Obstetrics and Gynaecology, University of Homburg/Saar. Of 222 participated pregnant women 26% were act ive smokers and 46% passive smokers. After adjustment a mean reduction in b irth weight of 228 g was found in infants born to smokers, without dose cor relation. Birth weight was not significantly reduced in infants born to pas sive smokers. There was no influence to the gestational age. A high correla tion was established between maternal serum cotinine and umbilical cotinine (r = 0.91). In actively smoking mothers there was a positive correlation b etween vitamin E concentration and corrected infant birth weight (r=0.33). Actively smoking mothers with children with a birthweight lower than the 25 th percentile had significantly (p < 0.007) oftener lower vitamin E concent rations. Smoking increases the consumption of vitamin E, so that there is o verproduction of peroxides and a reduction in prostacyclin. This lack of pr ostacyclin may lead to diminished perfusion of the placenta and may explain the birth weight reduction in smoker children.