Pregnant women who experience severe nausea and vomiting have nearly fourfold greater odds of prenatal marijuana use compared with women not experiencing nausea and vomiting, according to data from 220,510 first-trimester screenings.
In a research letter published in JAMA Internal Medicine, researchers reported the results of a health care system data analysis, which found a 3.80-fold greater prevalence of prenatal marijuana use among women with severe nausea and vomiting in pregnancy, compared with those who did not experience nausea and vomiting.
Among women with mild nausea and vomiting in pregnancy, there was still a significant twofold higher prevalence of marijuana use.
“Use of marijuana, an antiemetic, is increasing among pregnant women, and data from two small surveys indicate that women self-report using marijuana to alleviate nausea and vomiting in pregnancy (NVP),” wrote Kelly C. Young-Wolff, PhD, of the division of research at Kaiser Permanente Northern California, Oakland, and her coauthors.
In this study, 2% of the women experienced severe and 15% experienced mild nausea and vomiting during pregnancy.
The overall prevalence of marijuana use – assessed either by self-report or toxicological test findings – was 5.3%, with 0.7% positive on self-report only, 3.1% positive on toxicologic testing only, and 1.5% positive on both.
The authors said the findings supported the hypothesis that pregnant women were using marijuana to self-medicate for NVP. However, they also noted that clinicians may diagnose NVP more frequently among women who report using marijuana to treat it.
Dr. Young-Wolff and her coauthors said that they would not have been able to distinguish prenatal marijuana use from use before the women knew they were pregnant, “and misclassification is possible given variability in the time that marijuana is detectable in urine.
“The health effects of prenatal marijuana use are unclear, and national guidelines recommend that pregnant women discontinue use,” the authors wrote. “Patients with NVP should be screened for marijuana use and educated about effective and safe NVP treatments.”
The study was supported by the National Institute on Drug Abuse and the National Institute of Mental Health. No conflicts of interest were declared.
SOURCE: Young-Wolff K et al. JAMA Intern Med. 2018 Aug 20. doi: 10.1001/jamainternmed.2018.3581.