Association of Marijuana Use with Nausea and Vomiting of Pregnancy


      To evaluate if marijuana use is associated with nausea and vomiting in early pregnancy. Our secondary objective was to compare prescription antiemetic use among patients with and without marijuana use.

      Study Design

      Secondary analysis of a prospective, multicenter study of nulliparous individuals recruited from 2010-13 at eight U.S. centers (nuMoM2b). Participants who completed a Pregnancy-Quantification of Emesis and Nausea (PUQE) tool and provided a urine sample at the first nuMoM2b study visit (mean GA 11 weeks) were included. Marijuana exposure was ascertained by urine immunoassay for 11-nor-9-carboxy-delta-9-tetrahydrocannabinol (THC-COOH) and confirmed with liquid chromatography tandem mass spectrometry (cutoff 15 ng/mL). Quantified levels of THC-COOH were normalized with urine creatinine (Cr). The primary outcome was PUQE score (moderate/severe vs mild/none) with PUQE components and prescription antiemetic use as secondary outcomes. Multivariable logistic regression for PUQE outcomes adjusted for maternal age, body mass index, prescription antiemetic use, and gestational age.


      Overall, 5.8% (95% CI 5.4-6.3%) of 9,250 participants were THC-COOH positive. Baseline characteristics differed between those with and without detectable THC-COOH (Table 1). Individuals with detectable THC-COOH reported a higher frequency and severity of symptomatic nausea and vomiting (Table 2). In adjusted analyses, incrementally higher THC-COOH (500 ng/mg creatinine) was associated with moderate to severe nausea by PUQE score (aOR 1.6, 95% CI 1.1-2.2) and vomiting (aOR 1.9, 95% CI 1.3-2.7). Those with detectable THC-COOH were more likely to report the use of prescribed antiemetic medications (18 vs 12%, p< 0.001); however, most took only one antiemetic.


      Using a validated instrument to assess nausea and urine drug assays for ascertainment of use, marijuana use was associated with early pregnancy nausea and vomiting in a large, unselected, multistate cohort. This finding was despite higher use of prescription antiemetics in those with detectable THC-COOH.
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