Urine drug screening in mothers and newborns

J. D. Osterloh and B. L. Lee
Department of Laboratory Medicine, University of California, San Francisco.

A retrospective analysis of comprehensive urine drug screening was performed during a 13-month period on specimens submitted from the Neonatal Nursery and Obstetrics/Gynecology wards at San Francisco (Calif) General Hospital (mothers, N = 601; newborns, N = 339). Of mothers and newborns, respectively, 19.2% and 15.3% of all admissions during this period were screened; 68.2% and 63.1% of urine samples submitted were positive for any drug; 38.8% and 21.1% of screens were positive for more than one drug; and 45.8% and 41.6% were positive for cocaine. In mother-newborn pairs (N = 191) where urine samples were submitted within 4 days of each other, an 84% concordance was shown for cocaine and 67% for methadone, but concordance was much less for other drugs (less than 21%). These results indicate that cocaine was the most common drug detectable in the peripartum period and that both mothers and newborns should be tested to confirm the suspicion of drug effect or withdrawal in the newborn.