Nicotine and metabolites in meconium as evidence of maternal cigarette smoking during pregnancy and predictors of neonatal growth deficits.
BACKGROUND
Many women continue tobacco use during pregnancy despite known adverse consequences on neonatal growth and development. Testing meconium, the first neonatal feces, for tobacco biomarkers offers objective evidence of prenatal tobacco exposure. However, relationships between the amount, frequency, and timing of cigarette smoking during gestation and tobacco biomarker meconium concentrations and neonatal outcomes are unclear.


METHODS
Eighty-seven pregnant women provided detailed self-reports of daily tobacco consumption throughout pregnancy. Nicotine, cotinine, and trans-3'-hydroxycotinine were quantified in neonatal meconium by liquid chromatography-tandem mass spectrometry.


RESULTS
Among nonsmokers, all meconium specimens were negative, whereas nearly all meconium specimens were positive if the mother self-reported tobacco use into the third trimester. Tobacco biomarker concentrations were significantly albeit weakly correlated with mean cigarettes per day in the third trimester. Reduced birth weight, gestational age, or head circumference were observed if meconium contained one or more tobacco biomarkers, but deficits did not correlate with biomarker concentrations.


CONCLUSIONS
While previously thought to reflect second and third trimester drug exposure, meconium appears to reliably identify only third trimester drug use. While a 10 ng/g nicotine, cotinine, or trans-3'-hydroxycotinine cutoff in meconium was previously proposed to differentiate tobacco-exposed from nonexposed or passively exposed neonates, improved maternal self-reporting techniques in this cohort suggest that a lower cutoff, equivalent to the analytic limits of quantification, is more appropriate.
Gray
Teresa R
TR
Chemistry and Drug Metabolism, Intramural Research Program, National Institute on Drug Abuse, National Institutes of Health, Baltimore, MD 21224, USA.
Eiden
Rina D
RD
Leonard
Kenneth E
KE
Connors
Gerard
G
Shisler
Shannon
S
Huestis
Marilyn A
MA
D000293:Adolescent; D000328:Adult; D002853:Chromatography, Liquid; D003367:Cotinine / Q000031:analogs & derivatives / Q000032:analysis / Q000378:metabolism; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008431:Maternal-Fetal Exchange; D008470:Meconium / Q000737:chemistry* / Q000378:metabolism*; D009538:Nicotine / Q000032:analysis* / Q000378:metabolism*; D011247:Pregnancy; D011264:Pregnancy Trimesters; D012907:Smoking / Q000009:adverse effects* / Q000378:metabolism*; D053719:Tandem Mass Spectrometry; D055815:Young Adult
C001381:hydroxycotinine; D009538:Nicotine; D003367:Cotinine