By Katherine Rivlin, MD, MSc
Section Chief, Family Planning, University of Chicago
Isolated marijuana use, when used as an indication for urine drug screening during the labor and delivery period, poorly predicts concomitant use of other nonprescribed substances. However, use of the screening brings real risk of inequitable harm.
Rubin A, Zhong L, Nacke L, et al. Urine drug screening for isolated marijuana use in labor and delivery units. Obstet Gynecol 2022; Sep 9. doi: 10.1097/AOG.0000000000004930. [Online ahead of print].
Marijuana is the most commonly used illicit drug in pregnancy, with a self-reported prevalence of 2% to 5% of pregnancies.1 The American College of Obstetricians and Gynecologists (ACOG) discourages marijuana use in pregnancy because of concerns for impaired fetal neurodevelopment and the adverse effects of smoking. ACOG also recommends universal screening prior to or in early pregnancy for tobacco, alcohol, and other nonmedical drug use, including marijuana use.2
Although ACOG recommends universal screening, no clear or evidence-based guidelines exist for toxicology testing.3 In practice, testing often is obtained inconsistently. Many institutions use self-reported marijuana use as an indication for testing. However, the association between marijuana use and concomitant use of other nonprescribed substances is not well defined. Positive toxicology results can bring significant repercussions for patients, and mounting evidence suggests that social and demographic factors may play a significant role in the decision to perform toxicology testing.4
This study sought to examine urine drug screen results and subsequent patient and neonatal outcomes among patients who underwent toxicology testing for isolated marijuana use at the time of delivery. The authors hypothesized that urine drug screens performed because of isolated marijuana use would infrequently identify other nonprescribed substance use.
This retrospective cohort study included all patients admitted for delivery from Jan. 1, 2020, to Dec. 31, 2020, at an urban academic center. At this center, urine drug screening is performed based on specific criteria, including isolated marijuana use. Verbal screening of all patients occurs at the time of admission and through a review of prenatal records. Patients who underwent urine drug screening after receiving analgesia were excluded. The team compared demographic data, urine drug screen results, and subsequent neonatal outcomes between patients who underwent urine drug screening because of isolated marijuana use and those who did not undergo urine drug screening.
Of 3,494 deliveries included in the study, 754 (21.5%) underwent a urine drug screen. Most patients who had urine drug testing were Black (70.5%). Positive urine drug screens for nonprescribed substances other than marijuana were more likely among white patients (33.8%) compared to Black patients (10.5%, P > 0.001). The most common reason (45.7%) that urine drug screening occurred was for isolated marijuana use.
When compared to those patients who did not undergo urine drug screening, those patients who did undergo urine drug screening for isolated marijuana use were more likely to be younger (median age 25 years vs. 29 years; P < 0.001), to be Black (adjusted odds ratio [aOR], 2.58; 95% confidence interval [CI], 1.94-3.41), and to use public health insurance (aOR, 1.54; 95% CI, 1.21-1.95). No differences occurred between the two cohorts when comparing neonatal outcomes, such as Apgar scores < 7 or low or very low birth weight.
Isolated marijuana use identified only 1.5% of urine drug screens that were positive for substances other than marijuana. However, of those whose urine drug screen was positive for marijuana after undergoing screening for isolated marijuana use, 177 (89.9%) were mandatorily reported to the state child abuse hotline. Of those patients reported to the child abuse hotline, 20.9% were white and 79.1% were Black. All but one infant were discharged home in the patients’ custody.
COMMENTARY
Although isolated marijuana use was the most common indication for urine drug screening on this labor and delivery unit, this specific criterion rarely identified concomitant exposure to other illicit substances. Neonatal outcomes were similar between the two groups, although the study was not powered to assess these differences. In other words, the study team documented no real benefit of this screening criterion.
Yet, this screening criterion demonstrated real harms. Its use disproportionately targeted already marginalized groups: patients who were young, who were Black, or who were using public health insurance. The study team documented the subsequent consequences, including mandatory state reporting. When positive, toxicology test results can bring significant repercussions to patients, including stigmatization, criminalization, prolonged hospitalization, and familial separation.5
As more states legalize marijuana, its prevalence in pregnancy also will increase. Currently, the available data do not suggest an association between marijuana use in pregnancy and perinatal mortality.6 Tobacco also is legal to use, but unlike marijuana use, it has clearly established associations between its use and significant perinatal risks. Self-reported tobacco use among patients should prompt counseling on these risks and on resources for smoking cessation. However, tobacco use does not bring mandatory reporting requirements.7 Clinicians should consider treating self-reported marijuana use similarly to self-reported tobacco use in prenatal and peripartum care.
Current screening guidelines that include isolated marijuana use to prompt a urine drug screen are not evidence-based. This study demonstrates not only their abysmal sensitivity and lack of association with neonatal outcomes, but real potential for harms that disproportionally affect populations that already are stigmatized and experiencing significant healthcare disparities. Clinicians should consider this risk profile when implementing urine drug screening policies on labor and delivery.
REFERENCES
- [No authors listed]. Committee Opinion No. 722: Marijuana use during pregnancy and lactation. Obstet Gynecol 2017;130:e205-e209.
- [No authors listed]. Committee Opinion No. 633: Alcohol abuse and other substance use disorders: Ethical issues in obstetric and gynecologic practice. Obstet Gynecol 2015;125:1529-1537.
- [No authors listed]. Committee Opinion No. 711: Opioid use and opioid use disorder in pregnancy. Obstet Gynecol 2017;130:e81-e94.
- Perlman NC, Cantonwine DE, Smith NA. Toxicology testing in pregnancy: Evaluating the role of social profiling. Obstet Gynecol 2020;136:607-609.
- Price HR, Collier AC, Wright TE. Screening pregnant women and their neonates for illicit drug use: Consideration of the integrated technical, medical, ethical, legal, and social issues. Front Pharmacol 2018;9:961
- Warshak CR, Regan J, Moore B, et al. Association between marijuana use and adverse obstetrical and neonatal outcomes. J Perinatol 2015;35:991-995.
- [No authors listed]. Tobacco and nicotine cessation during pregnancy: ACOG Committee Opinion, Number 807. Obstet Gynecol 2020;135:e221-e229.
