(358) Examining maternal medication administration prior to urine drug screening

Thursday, January 30, 2025

10:30 AM – 12:30 PM

Submitting Author and Presenting Author(s)

Siera Lunn, BS (she/her/hers)

Duke University School of Medicine
Durham, North Carolina, United States

Coauthor(s)

Adwoa A. Baffoe-Bonnie, BS

Duke University School of Medicine
Durham, North Carolina, United States
JC

Janea Cato

Clinical Research Specialist Sr.
Duke University School of Medicine
Durham, North Carolina, United States
LF

Lena Fried, BS

Clinical Research Coordinator
Duke University School of Medicine
Durham, North Carolina, United States
LS

Leyi Sun, BS

Duke University School of Medicine
Durham, North Carolina, United States
TT

Tracy Truong, MS

Biostatistician
Duke University School of Medicine
Durham, North Carolina, United States
Sarahn M. Wheeler, MD

Associate Professor of Obstetrics and Gynecology
Duke University School of Medicine
Durham, North Carolina, United States
Jennifer J. M. Cate, MD

Maternal Fetal Medicine Fellow
Duke University School of Medicine
Durham, North Carolina, United States

Objective: Urine drug screening (UDS) is prevalent on many labor and delivery (L&D) units. However, several common medications can cause a false positive UDS. We assessed how often pregnant patients received medications associated with false positive results and whether patient characteristics were associated with receipt of these medications.

Study Design: Retrospective cohort study of patients presenting to L&D at a single academic center between June 10, 2021, and May 31, 2022, who had UDS following implementation of a maternal substance use screening protocol. Primary outcomes included the proportion of patients who received medications associated with false positives prior to UDS and the proportion of patients with a positive UDS after receipt of these medications (Table 1). Additionally, we examined whether patient age, race, ethnicity, or insurance status differed between those who received these medications and those who did not. Kruskal Wallis and Chi square tests were used to compare categorical variables.

Results: 140 patients underwent UDS. Of those, 30 (21.4%) received medications associated with false positives, and 12 (8.6%) subsequently tested positive (Table 2). Among these 12 patients, the most commonly detected substance was THC (n = 7, 58.3%). The majority of patients tested negative and did not receive any associated medications beforehand. We found no significant differences in age, race, ethnicity, or insurance status, or primary language between those who received these medications and those who did not.

Conclusion: Few patients were administered medications associated with false positives prior to UDS. Given the screening nature and potential for false positives in UDS, iatrogenic false positive results should be considered in instances of confounding administration. Patient characteristics were not associated with receiving medications that can cause false positives. Future research should explore the frequency of confirmatory testing in pregnant patients, the steps taken after a potentially confounded positive result, and whether these vary based on patient demographics.