(70) Clinically Actionable Newborn Toxicology Results are Uncommon Under New Policy

Background & Introduction: Toxicology testing of the birthing person and newborn at delivery can be used to assess in utero substance exposure but is often inequitably utilized. Many hospitals across the country have changed their toxicology testing guidelines given documented racial disparities in testing and low clinical utility, but the impact of these policy changes has been under-studied. In November 2021, our hospital revised its risk-based perinatal toxicology testing policy to include a new requirement for written consent for both birthing person urine and newborn meconium testing; however, newborn urine testing could be performed with only parental assent. We sought to determine if the ability to decline multiple forms of testing would lead to under-identification of non-prescribed substance use, by evaluating the proportion of unexpected positive results within dyads which received only newborn toxicology testing.

Methods: Dyads who underwent perinatal toxicology testing between January 2022 and December 2023 at an academic medical center in New England were identified using electronic medical record review. Clinical rationales for testing under the new policy included birthing person signs and symptoms of intoxication or withdrawal, substance use disorder within a year of pregnancy, no prenatal care, prescribing of controlled substances during pregnancy, or newborn signs concerning for withdrawal. We extracted toxicology test indication, toxicology test type, and documentation of consent for all dyads. We calculated the proportion of dyads in which only newborn toxicology testing had been performed; due to infrequent documentation of the reasons for birthing person testing not being performed, we analyzed all newborn-only tested dyads as a proxy for cases in which the birthing person may have declined testing. Additional chart review of newborn-only tested dyads was then performed to collect information on toxicology test results, including presence of an unexpected toxicology result (defined as a positive result which could not have been predicted based on birthing person self-report, verbal screening, clinical history, or prescribed medication use), and subsequent clinical course in the case of an unexpected result.

Results: From January 2022 to December 2023, 7339 live newborns were delivered, with 107 dyads undergoing any toxicology testing. Toxicology testing was performed in the absence of birthing person testing in 39 newborns total. Two of 39 newborns (5.12%) had an unexpected positive result for cocaine; of these cases, 1 newborn had been tested for known parental use of non-prescribed substances, while 1 had been tested for parental use of prescribed medications for opioid use disorder (MOUD). There was an additional case of an unexpected newborn urine positive for fentanyl involving self-reported use of a non-prescribed opioid pill, which was attributed to the non-prescribed pill having been pressed with fentanyl given that the birthing person had not received an epidural. By testing indication within the newborn-only tested dyads, the rate of unexpected positive results was 28.57% within newborns tested for known non-prescribed substance use, 5.00% within newborns tested for use of prescribed MOUD, and 0.00% within newborns tested for other indications.

In all 3 cases with unexpected positive results, the unexpected positive result led to a change in clinical management, which was either breastfeeding counseling or monitoring for signs of toxicity or withdrawal. The social situation of the 2 infants with positive toxicology results for cocaine was investigated in the context of the known history of substance use, and, in one case, known non-prescribed opioid use during pregnancy; newborn toxicology testing showing results positive for cocaine may have contributed to the ultimate decision for those families to be separated on discharge from the newborn hospital stay.

Conclusion & Discussion: Our study found unexpected positive toxicology results leading to documented changes in newborn clinical management in 7.69% of newborn-only tested cases, with a higher rate in cases with active non-prescribed substance use during pregnancy. However, there was no new information added in over 90% of newborn-only tested dyads. This demonstrates that, under a new policy change requiring written informed consent for birthing person and newborn meconium testing, birthing persons frequently declined toxicology tests for reasons other than concealment of substance use. One limitation of our study’s approach is that we used presence of newborn-only testing as a proxy for birthing person declining testing, which may have led to misclassification of cases in which birthing person testing was not performed for another reason. The small sample size is another limitation, and we plan to update this analysis as more data become available. In summary, comprehensive information about substance use during pregnancy can often be obtained through prenatal birthing person screening rather than toxicology testing, which is optimal to provide responsive care and social supports prior to delivery.

References:
Habersham, L. L., Bianco, A. T., Kudrich, C. J., Woolfolk, C. L., Stern, T. A., Stone, J. L., & Hurd, Y. L. (2023). An Institutional Intervention on Toxicology Testing Reduces Inequities During the Birthing Hospitalization. American Journal of Obstetrics and Gynecology. https://doi.org/10.1016/j.ajog.2023.11.1254

Montoya-Williams, D., & Fleishman, R. (2023). Confronting The Harms Caused By Racism In Perinatal Drug Testing. Health Affairs Forefront. https://doi.org/10.1377/forefront.20230824.716788

Polak, K., Kelpin, S., & Terplan, M. (2019). Screening for substance use in pregnancy and the newborn. Seminars in Fetal and Neonatal Medicine, 24(2), 90–94. https://doi.org/10.1016/j.siny.2019.01.007

Siegel, M. R., Cohen, S. J., Koenigs, K., Woods, G. T., Schwartz, L. N., Sarathy, L., Chou, J. H., Terplan, M., Wilens, T., Ecker, J. L., Bernstein, S. N., & Schiff, D. M. (2023). Assessing the clinical utility of toxicology testing in the peripartum period. American Journal of Obstetrics & Gynecology MFM, 5(7), 100963. https://doi.org/10.1016/j.ajogmf.2023.100963