skip to Main Content

Cannabis use by pregnant women increased during pandemic

Large Kaiser Permanente study finds 25% rise in rate of use


A Kaiser Permanente analysis of more than 100,000 pregnancies in Northern California finds a 25% increase in the rate of cannabis use early in pregnancy after the pandemic began in spring 2020.

The analysis was reported in a research letter in the September 27 issue of JAMA. The study found that in the year before the pandemic, 6.75% of pregnant women were using cannabis in early pregnancy, and during the pandemic that rate rose to 8.14% of pregnant women.

Kelly Young-Wolff, PhD, MPH, research scientist, Division of Research.

The study did not determine why more pregnant women might be using cannabis. “Our previous research has shown that the prevalence and frequency of prenatal cannabis use is increasing over time and that pregnant women are more likely to use cannabis if they are depressed, anxious, or have experienced trauma. It’s very possible that more pregnant women are using cannabis in an attempt to self-medicate these issues during the pandemic,” said lead author Kelly Young-Wolff, PhD, MPH, a clinical psychologist and research scientist with the Kaiser Permanente Division of Research.

“The stay-at-home mandates, concerns about getting COVID-19, economic challenges, increased child care burden, and other difficult aspects of the pandemic could contribute to pregnant women feeling more stressed and depressed during this time,” Young-Wolff added.

The study examined urine toxicology tests for cannabis from the first prenatal visit for 100,005 pregnancies (involving 95,412 women) at Kaiser Permanente in Northern California from January 2019 through December 2020, comparing positive tests in a 15-month pre-pandemic period with those during the pandemic.

The trend is concerning because of potential risks to newborns such as low infant birth weight and potential neurodevelopmental effects on children associated with prenatal cannabis use, said senior author Lyndsay Avalos, PhD, MPH, a research scientist at the Division of Research. “As the pandemic continues it will be important to identify subgroups of women who are most likely to use cannabis during pregnancy so we can provide more targeted interventions.”

Lyndsay Avalos, PhD, MPH, research scientist with the Division of Research.

It is also important for clinicians to discuss cannabis use with their patients. “We need to get the word out more effectively that cannabis is not a healthy choice during pregnancy,” said co-author Deborah Ansley, MD, regional medical director for Kaiser Permanente’s Early Start prenatal health program. “Women may be trying to manage nausea or mood problems early in pregnancy or may simply be continuing a habit from before they became pregnant. Clinicians — and people who work in cannabis dispensaries — need to help educate women that during pregnancy they should abstain from any type of cannabis use because of potential health risks to their babies.”

The research did not differentiate among types of cannabis products used or concentrations of CBD or THC used by women. Young-Wolff and Avalos have funding from the National Institute on Drug Abuse to carry out more in-depth, long-term research on use of various types of cannabis products in pregnancy and their impact on the health of mothers and children.

In a recent editorial in JAMA Network Open, Young-Wolff and 2 colleagues also highlighted the need for equitable access to supportive and nonpunitive substance use treatment and recommended legal and regulatory policies to protect infants and children while not imposing criminal or discriminatory burdens on vulnerable communities.

The study was funded by grants from the National Institute on Drug Abuse.

Co-authors also included Thomas Ray, MBA, Stacey E. Alexeeff, PhD, Sara R. Adams, MPH, and Monique B. Does, MPH, all of the Division of Research.

# # #

About the Kaiser Permanente Division of Research

The Kaiser Permanente Division of Research conducts, publishes and disseminates epidemiologic and health services research to improve the health and medical care of Kaiser Permanente members and society at large. It seeks to understand the determinants of illness and well-being, and to improve the quality and cost-effectiveness of health care. Currently, DOR’s 600-plus staff is working on more than 450 epidemiological and health services research projects. For more information, visit or follow us @KPDOR.

This Post Has 0 Comments

Leave a Reply

Your email address will not be published. Required fields are marked *

Back To Top