Abstract
Smoking during pregnancy results in an average 200 gm reduction in birthweight (BW) and is associated with a two to threefold increase in low BW infants (<2500 gm). The number of cigarettes smoked each day is, however, an imprecise measure of the extent of exposure to the fetus to cigarette smoke components. In an attempt to improve precision, biochemical markers of cigarette smoke intake have been developed, among than cotinine, which is a metabolic derivative of nicotine, specific to tobacco smoke inhalation. We have developed an assay for cotinine and studied the relative predictive power of a single serum cotinine level versus self-reported numbers of cigarettes smoked in relation to BW on 6,689 second trimester women. Women who answer a smoking question do so reliably as judged by cotinine (sensitivity-95%; specificity=95%). Serum cotinine levels above 10 ng/mL are defined to be consistent with cigarette smoking. Values between 10 and 25 ng/mL are associated with a lowered mean BW of 75 gm. As cotinine concentration increases in serum, mean BW continues to fall, reaching an extreme of 420 gm with cotinine values above 200 ng/mL. A two way analysis of variance shows serum cotinine to be a more sensitive predictor of BW than self-reporting. Cotinine measurement is, therefore, a useful screening test to identify those smoking women at greatest risk of delivering low BW babies.
Article PDF
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Knight, G., Haddow, J., Paloroaki, G. et al. 555 COTININE VS. SELF-REPORTED CIGARETTE CONSUMPTION AS PREDICTORS OF BIRTHWEIGHT. Pediatr Res 19, 203 (1985). https://doi.org/10.1203/00006450-198504000-00585
Issue Date:
DOI: https://doi.org/10.1203/00006450-198504000-00585