Umbilical Cord Collection and Drug Testing to Estimate Prenatal Substance Exposure in Utah

Our primary objective was to estimate statewide prenatal substance exposure based on umbilical cord sampling. Our secondary objectives were to compare prevalence of prenatal substance exposure across urban, rural, and frontier regions, and to compare contemporary findings to those previously reported.

We performed a cross-sectional prevalence study of prenatal substance exposure, as determined by umbilical cord positivity for 49 drugs and drug metabolites, through the use of qualitative liquid chromatography-tandem mass spectrometry. All labor and delivery units in Utah (N=45) were invited to participate. Based on a 2010 study using similar methodology, we calculated that a sample size of at least 1,600 cords would have 90% power to detect 33% higher rate of umbilical cords testing positive for any substance. Deidentified umbilical cords were collected from consecutive deliveries at participating hospitals. Prevalence of prenatal substance exposure was estimated statewide and by rurality using weighted analysis.

From November 2020 to November 2021, 1,748 cords (urban n=988, rural n=384, frontier n=376) were collected from 37 hospitals, representing 92% of hospitals that conduct 91% of births in the state. More than 99% of cords (n=1,739) yielded results. Statewide, 9.9% (95% CI 8.1-11.7%) were positive for at least one substance, most commonly opioids (7.0%, 95% CI 5.5-8.5%), followed by cannabinoid (11-nor-9-carboxy-delta-9-tetrahydrocannabinol [THC-COOH]) (2.5%, 95% CI 1.6-3.4%), amphetamines (0.9%, 95% CI 0.4-1.5), benzodiazepines (0.5%, 95% CI 0.1-0.9%), alcohol (0.4%, 95% CI 0.1-0.7%), and cocaine (0.1%, 95% CI 0-0.3%). Cord positivity was similar by rurality (urban=10.3%, 95% CI 8.3-12.3%, rural=7.1%, 95% CI 3.5-10.7%, frontier=9.2%, 95% CI 6.2-12.2%, P=.31) and did not differ by substance type. Compared with a previous study, prenatal exposure to any substance (6.8 vs 9.9%, P=.01), opioids (4.7 vs 7.0% vs 4.7%, P=.03), amphetamines (0.1 vs 0.9%, P=.01) and THC-COOH (0.5 vs 2.5%, P<.001) increased.

Prenatal substance exposure was detected in nearly 1 in 10 births statewide.