Maternal Marijuana Exposure and Birth Weight: An Observational Study Surrounding Recreational Marijuana Legalization.

OBJECTIVE: This study aimed to study the relationship between prenatal marijuana and infant birth weight using natural cohorts established before, during and after the 20-month lapse between legalization and legal recreational sales in Washington State. STUDY DESIGN: Over 5 years, 5,343 pregnant women with documented urine drug screen (UDS) results delivered at Tacoma General Hospital or Good Samaritan Hospital. Maternal medical data were extracted for three delivery cohorts established based on before (T1), during (T2), and after legalization (T3) of recreational marijuana and legalized availability. Univariate and multivariate models were created to study marijuana exposure on infants' birth weight. RESULTS: Marijuana exposure increased the risk of low birth weight (LBW; odds ratio [OR] = 1.42, 95% confidence interval [CI]: 1.01-2.01). This was more pronounced in full-term babies (OR = 1.72, 95% CI: 1.10-2.69), and was independently associated with a higher risk for small for gestational age (SGA; OR = 1.51, 95% CI: 1.49-1.53). The associations between marijuana exposure and SGA were maintained in cohort-specific models (OR = 1.53, 95% CI: 1.01-2.32 for T2, and OR = 1.43, 95% CI: 1.01-2.02 for T3, respectively). CONCLUSION: Marijuana exposure verified by UDS was associated with LBW and SGA. However, recreational marijuana legalization and availability did not have direct impact on newborns' risk of LBW or SGA.

Demographic Discrepancies in Prenatal Urine Drug Screening in Washington State Surrounding Recreational Marijuana Legalization and Accessibility.

OBJECTIVES: This study evaluated demographic patterns related to prenatal cannabinoid urine drug screening (UDS) over a 5-year period during which recreational marijuana was legalized and became accessible in Washington State. METHODS: Using electronic health record data, we performed a retrospective analysis for deliveries occurring over a 5-year period that encapsulated the transitions to marijuana legalization and legal access. For three cohorts of women delivering prior to legalization, between legalization and accessibility, and following accessibility, the UDS completion rate and screening demographic characteristics were assessed using Chi-squared tests and multivariate logistic regression. RESULTS: 25,514 deliveries occurred between March 2011 and March 2016. A significantly higher percentage of women underwent UDS post-accessibility (24.5%) compared to pre-legalization (20.0%, p < 0.001). A corresponding increase was not observed in the percentage of marijuana-positive UDS in tested patients (22.7% vs. 23.3%, p = 0.86). African American women had 2.8 times higher odds than Latinas of being tested, 2.1 times higher odds than Asian women, 1.7 times higher odds than White women, and 1.4 times higher odds than women of other races (all p < 0.001). Subsidized insurance status was also strongly associated with increased likelihood of testing (aOR = 3.5, p < 0.001). CONCLUSIONS FOR PRACTICE: Prenatal UDS testing patterns changed as recreational marijuana possession and accessibility became legal. Demographic discrepancies in testing reveal biases related to race and insurance status, which may be a proxy for socioeconomic status. As such discrepancies are potential contributors to health outcome disparities, it is important for providers and health care systems to examine their practices and ensure they are being appropriately, equally, and justly applied.