Estimating fetal morbidity and mortality resulting from cigarette smoke exposure by measuring cotinine levels in maternal serum
Haddow, J.E.; Knight, G.J.; Palomaki, G.E.; Haddow, P.K.
Progress in Clinical and Biological Research 281: 289-300
1988
ISSN/ISBN: 0361-7742 PMID: 3174713 Document Number: 318525
An essay for cotinine levels in maternal serum was used to define cigarette smoking exposure level and fetal morbidity and mortality. Cotinine, a metabolite of nicotine, has a circulating half-life of about a day, making it more reliable than nicotine as an indicator or active and passive smoke exposure. Maternal smoking has been linked in previous studies with low Apgar scores, low birthweight, decreased placental blood flow, fetal activity, fetal breathing movements, depressed prostacyclin synthesis in umbilical artery, increased perinatal mortality and spontaneous abortion. In this study, 8063 2nd trimester pregnant women whose serum had been collected and frozen in 1979-1983 were analyzed for smoking habit determined from intake questionnaires. Cotinine levels correlated with 95% of those reporting no smoking, and 93% of those reporting smoking. Smokers with cotinine 10 ng/ml was higher than expected, possible because some women quit before blood was drawn. Cotinine levels did not correlate as well as number of cigarettes per day reported. There was a significant association between serum cotinine and birthweight at the 10 and 20 cigarette/day level, and a trend toward a link between cotinine and fetal deaths in 2nd and 3rd trimesters. Among infants of the 30% of women exposed to passive smoke whose serum cotinine levels were 1 ng/ml, the average birth weight was 107 g lower than those of non-exposed women, a difference remaining after controlling for maternal weight and height, infant's sex, maternal age, gravidity and education.