Cotinine (COT)

Prenatal Screening Laboratory

Radioimmunoassay

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Specimen Required:

Serum: 2 mL or

Urine: 1 mL or

Saliva: 1 mL (spun and separated);

Refer to Specimen Collection and Preparation

Days Test Set Up:

Run as needed

Analytic Time:

24 hours

Reference Values:

<10 ng/mL = no significant exposure

10-20 ng/mL = Passive exposure

>20 ng/mL= Active smoker

CPT Code(s):

83887

Relevance:

Cotinine measurement can determine the amount of cigarette smoke absorbed into the circulation.

Notes:

Elevated cotinine levels during pregnancy are associated with decreased birth weight. Patient pamphlet "Questions and Answers About Cotinine Testing", as well as "Provider Frequently Asked Questions" are available from the FBR.

Urinary cotinine levels can be used to assess exposure to environmental tobacco smoke in children with asthma.

Reference(s)

• Haddow JE, Knight GJ, Kloza EM, Palomaki GE, Wald NJ: Cotinine-assisted intervention to reduce smoking and low birthweight delivery. Br J Obstet Gynæcol, 98:859-865, 1991.
• Haddow JE, Knight GJ, Palomaki GE, Kloza EM, Wald NJ: Cigarette consumption and serum cotinine in relation to birthweight. Br J Obstet Gynæcol, 94:678-681, 1987.
• Chilmonczyk BA, et al: Association between exposure to environmental tobacco smoke and exacerbations of asthma in children, N Engl J Med, 328: 1665-1669, 1993.