[Effect of smoking and antioxidant vitamin concentrations of pregnant patients on birth weight of newborn infants].

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