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Updated: Jul 9, 2026

Assessment and Evaluation of the High Risk Neonate: The NICU Network Neurobehavioral Scale
Published on: August 25, 2014
Prenatal caffeine assessment: fetal and maternal biomarkers or self-reported intake?
Laura M Grosso1, Elizabeth Triche, Neal L Benowitz
1Yale Center for Perinatal, Pediatric and Environmental Epidemiology, Yale University School of Medicine, Department of Epidemiology and Public Health, One Church Street, New Haven, CT 06510, USA. laura.grosso@yale.edu <laura.grosso@yale.edu>
Purpose:
We sought to examine associations among measures of caffeine exposure, including maternal urine, umbilical cord blood, and maternal self report.
Methods:
Pregnant women were recruited from 56 obstetric practices and 15 clinics associated with six hospitals in Connecticut and Massachusetts between September 1996 and January 2000; 3633 women were enrolled. Maternal urine throughout pregnancy and umbilical cord blood samples were analyzed for caffeine, paraxanthine, theophylline, and theobromine. Maternal caffeine intake was assessed throughout pregnancy.
Results:
Urinary and cord blood biomarkers were correlated with reported intake throughout pregnancy (range r = 0.35-0.66; p < 0.0001). Infants of smokers had greater cord blood concentrations of paraxanthine, reflecting faster caffeine metabolism in smokers, and cord blood paraxanthine levels were more strongly correlated with intake in smokers.
Conclusion:
Maternal self reported intake may still be the optimal and most valid measure of antenatal caffeine exposure, since biomarkers do not reflect exposure over pregnancy.
