We investigated the utility of maternal cotinine concentration as a predictor of preterm and small-for-gestational-age (SGA) deliveries. Subjects were randomly selected from antenatal clinics, and their serum cotinine concentrations at approximately 16 weeks' gestation were compared with self-reports of smoking. The value of these measures in predicting preterm and SGA deliveries was examined, using likelihood ratios and logistic regression, for 845 women with singleton, live births. Smoking status alone (defined by self-report or cotinine) only weakly predicted preterm or SGA delivery. Self-reported moderate/high smoking (top 15% of smokers) had a likelihood ratio (LR) of 2 and a positive predictive value (PPV) of 17%. In contrast, moderate/high cotinine concentration (top 15% of smokers) had an LR of 5 and a PPV of 33%. The predictive value of cotinine was independent of associated maternal characteristics. Cotinine concentration may therefore be a useful predictor of poor pregnancy outcome, and should be considered as a screening tool.
HaddowJEPalomakiGEKnightGJ. Use of serum cotinine to assess accuracy of self-reported non-smoking. BMJ1986; 293: 1306.
2.
FordRPKTappinDMSchluterPJWildCJ. Smoking during pregnancy: how reliable are maternal self-reports in New Zealand?J Epidemiol Community Health1996; 51: 246–51.
3.
WalshRARedmanSAdamsonL. The accuracy of self-report of smoking status in pregnant women. Addict Behav1996; 5: 675–9.
4.
EskenaziBPrehnAWChristiansonRE. Passive and active maternal smoking as measured by serum cotinine: the effect on birthweight. Am J Public Health1995; 85: 395–8.
5.
BardyAHSeppalaTLillsundePKatajaJMKoskelaPPikkarainenJHilesmaaVK. Objectively measured tobacco exposure during pregnancy: neonatal effects and relation to maternal smoking. Br J Obstet Gynaecol1993; 100: 721–6.
6.
HaddowJEKnightGJPalomakiGEKlozaEMWaldNJ. Cigarette consumption and serum cotinine in relation to birthweight. Br J Obstet Gynaecol1987; 94: 678–81.
7.
HaddowJEKnightGJPalomakiGEKnightGJ. Second-trimester serum cotinine levels in nonsmokers in relation to birth weight. Am J Obstet Gynecol1988; 159: 481–4.
8.
SimpsonWJ. A preliminary report on cigarette smoking and the incidence of prematurity. Am J Obstet Gynecol1957; 73: 808–15.
9.
AbelEL. Smoking during pregnancy: a review of the effects on growth and development of offspring. Hum Biol1980; 52: 593–625.
10.
Anon. Smoke screen round the fetus. Lancet1989; 2: 1310–1.
ChienPFWKhanKSOgstonSOwenP. The diagnostic accuracy of cervico-vaginal fetal fibronectin in predicting preterm delivery: an overview. Br J Obstet Gynaecol1997; 104: 436–44.
13.
GalbraithRSKarchmarEJPeircyWNLowJA. The clinical prediction of intrauterine growth restriction. Am J Obstet Gynecol1979; 135: 281–6.
Office of Population Censuses and Surveys. Standard Occupational Classification. London: HMSO, 1990.
18.
World Health Organization. International Classification of Diseases, 9th revision with Federation Internationale de Gynécologie et d'Obstétrique (FIGO) definitions: an extract for use in obstetrical and gynaecological departments. Scottish Health Service Common Services Agency Information Services Division, Glasgow: Mackay and Inglis, 1980.
19.
CampbellDLemonJPritchardC. Clinical and birthweight standards for a total population in the 1980s. Br J Obstet Gynaecol1993; 100: 436–45.
20.
KnightCJWyliePHolmanMSHaddowJE. Improved I-125 radioimmunoassay for cotinine by selective removal of bridge antibodies. Clin Chem1985; 31: 118–21.
21.
Jaeschke R, Guyatt GH, Sackett DL for the Evidence-Based Medicine Working Group. User's guides to the medical literature. III. How to use an article about a diagnostic test. What are the results and will they help me in caring for my patients?JAMA1994; 271: 703–7.
22.
FaganJT. Nomogram for Bayes' theorem. N Engl J Med1975; 293: 257.
23.
BottingBCooperJ. Analysing fertility and infant mortality by mother's social class as defined by occupation — part II. Popul Trends1993; 74: 27–33.
24.
Joint Health Surveys Unit: Social and Community Planning Research. Health Survey for England 1995. A survey carried out on behalf of the Department of Health. Vol 1: Findings, Prescott-ClarkePPrimatestaP, eds. HMSO: London, 1997.
25.
CummingsSRRichardRJ. Optimum cutoff points for biochemical validation of smoking status. Am J Public Health1988; 78: 574–5.
26.
WagenknechtLEBurkeGLPerkinsLLHaleyNJFriedmanGD. Misclassification of smoking status in the CARDIA study: a comparison of self-report with serum cotinine levels. Am J Public Health1992; 82: 33–6.
27.
JarvisMJTunstall-PedoeHFeyerbendCVesseyCSaloojeeY. Comparison of tests used to distinguish smokers from nonsmokers. Am J Public Health1987; 77: 1435–8.
28.
AlbermanEPharoahPChamberlainG. Smoking and the fetus. Lancet1977; 2: 36–7.
29.
BenowitzNLKuytFJacobPJonesRTOsmanA. Cotinine disposition and effects. Clin Pharmacol Ther1983; 34: 604–11.
30.
MainDMGabbeSGRichardsonDStrongS. Can preterm deliveries be prevented?Am J Obstet Gynecol1985; 151: 892–8.
31.
Muller-HeubachEGuzickDS. Evaluation of risk scoring in preterm birth prevention study of indigent patients. Am J Obstet Gynecol1989; 160: 829–37.
