Cannabis Legalization's Impact on Prenatal Marijuana Use


Findings from a study in JAMA Network Open reveal valuable insight into the way cannabis legalization has impacted the perceptions of pregnant women who use cannabis in the US.

All but 4 states in the US have legalized some form of cannabis use and 19 states have fully legalized it for adult recreational use.1 While providers and national organizations recommend against prenatal cannabis use, the frequency and rate at which pregnant women are using cannabis continues to increase in the US. Most pregnant women use cannabis to prevent nausea and vomiting.2

Prenatal cannabis use may result in adverse fetal outcomes, including low birth weight and neurodevelopmental issues in childhood.2 Understanding the impact of cannabis legalization and its role in prenatal cannabis use from the perspective of pregnant women is crucial for ob-gyns to offer effective, personalized care and counsel to patients. It can also contribute to educational materials, public health campaigns, and policy adaptations in the future.

Findings from a study from Kaiser Permanente Northern California (KPNC)—a large integrated health care delivery system with more than 4 million members—were published recently in JAMA Network Open, revealing valuable insight into how women who use cannabis during pregnancy perceive the impacts of cannabis legalization.3

In general, the study found that women perceived legalization to mean greater access and exposure to cannabis, increased acceptance, and greater trust in cannabis retailers. Perhaps the most important finding, however, was the idea that legalization gave them greater confidence and willingness to discuss cannabis use during pregnancy with their provider. One woman said legalization empowered her to have an honest discussion with her doctor that ultimately led to her quitting use for the duration of her pregnancy.3

Researchers from KPNC conducted the qualitative study using data from the system’s universal prenatal screening questionnaire that women are given on entrance to prenatal care, at approximately 8 week’s gestation. They prioritized women who reported daily or weekly prenatal cannabis use and focused their efforts primarily on non-Hispanic Black and non-Hispanic White pregnant women—the populations with the highest prevalence of prenatal cannabis use in KPNC in recent years.4 Researchers also reviewed electronic health records for any documented pregnancy loss to confirm that the women were still pregnant. Eligible women were contacted with an invitation to participate or opt-out, asked to consent and then schedule a focus group. More than 60% of the eligible women did not schedule focus group participation for various reasons, including those who opted out, had time conflicts and incomplete consent processes.

Over the course of 4 weeks (November 17 to December 17, 2021), 51% of women scheduled (104) participated in 1 of 18 virtual focus groups, each with 1 to 6 participants per group and a duration of 90 minutes. Researchers grouped women and focus group leaders together based on race and ethnicity for congruency and to recognize the role race and ethnicity play in the experiences of pregnant women. The focus groups were made up of 43% non-Hispanic Black women and 57% non-Hispanic White women with a mean age of 30.3 (5.2) years. At the time of recruitment, most women (70%) reported daily prenatal cannabis use, 25% (13) reported weekly use, and 6% (3) participants reported monthly or less use.

Many women described ubiquitous cannabis retailers in their areas and believed that the easy access and convenience increased their desire to use cannabis. Several women reported cannabis retailers as accessible as liquor and corner stores, comparing the ease of accessibility to buying cigarettes or alcohol. Experiences with cannabis marketing and advertising varied among women, with many who had quit or cut down on use during pregnancy recalling that billboards and advertisements made them miss using or think about cannabis more often. Other women, however, reported little impact from cannabis marketing and advertising.

Evident among most women was the perception of reduced stigma around cannabis use, in general and during pregnancy. Such reduction may also be the reason they reported being more comfortable and open with their doctors. “I think that if it wasn’t legal and I didn’t feel comfortable speaking about it in the beginning with my doctor… I may still be smoking because

if I didn’t say anything and didn’t have those conversations with my doctor, I probably would have just kept doing it,” said a woman during one of the focus groups.

Women expressed mixed concerns regarding Child Protective Services (CPS) investigations. Something for ob-gyns to consider may be reassuring patients that CPS would not be called because of her prenatal cannabis use. Several women, however, reported continued strong concerns about potential CPS involvement after delivery. “I actually had a friend who has a CPS case out on her because she had tested positive for weed when she gave birth. So, that’s definitely a worry because some people are so against it. I don’t know if that’s in every case if that would happen. It’s kind of scary, you know?”

Another recurring theme among focus groups was the idea that cannabis retailer staff are knowledgeable, caring, and nonjudgmental. Most women viewed budtenders in retail outlets as experts on the benefits of cannabis use, including during pregnancy, with one woman likening them to a doctor of sorts. One woman said that budtenders “show you what’s best for

you… it’s kind of like the doctor, but not really.” A few other women, however, noticed that advice may vary in quality and suggested to go to a dispensary where “they know what they’re talking about.”

Ob-gyns and other prenatal care providers should leverage these findings, especially the notion that legalization gave women greater confidence and willingness to discuss cannabis use during pregnancy with their doctors. Ob-gyns should be trained and empowered to screen for and initiate conversations about prenatal cannabis use, provide nonjudgmental counseling and information about potential health risks, and refer women to alternative medicines or supplements that have been proven safe for pregnancy-related symptoms.

The issue regarding CPS involvement is also critical for ob-gyns to be aware of so they can provide accurate information to patients that is relevant in their state of practice.

In California, ob-gyns are not required to contact CPS or law enforcement when pregnant women screened positive for cannabis use and a positive toxicology test result at the time of delivery is not sufficient basis for reporting child abuse or neglect.5 However, prenatal cannabis use is still included in definitions of child abuse or neglect that can lead to termination of parental rights in many states5 even in states with full legalization.6

According to researchers and study authors, this implication further highlights the need to reform antiquated policies in states that criminalize prenatal substance use. Doing so, they concluded, may help avoid unintended negative public health consequences such as fewer patient-provider conversations, missed opportunities for education and referrals for alternative treatments.

This article originally appeared in Contemporary OB/GYN.


  1. Marijuana Legality By State. DISA. Published 2023. Accessed January 17, 2023.
  2. Skelton KR, Hecht AA, Benjamin-Neelon SE. Women’s cannabis use before, during, and after pregnancy in New Hampshire. Preventive Medicine Reports. 2020;20:101262. doi:10.1016/j.pmedr.2020.101262
  3. Young-Wolff KC, Foti TR, Green A, et al. Perceptions About Cannabis Following Legalization Among Pregnant Individuals With Prenatal Cannabis Use in California. JAMA Network Open. 2022;5(12):e2246912. doi:10.1001/jamanetworkopen.2022.46912
  4. Young-Wolff KC, Sarovar V, Tucker LY, et al. Trends in Cannabis Polysubstance Use During Early Pregnancy Among Patients in a Large Health Care System in Northern California. JAMA Network Open. 2022;5(6):e2215418. doi:10.1001/jamanetworkopen.2022.15418
  5. Child Welfare Information Gateway. Parental drug use as child abuse. Accessed October 18, 2022.
  6. Guttmacher Institute. Substance use during pregnancy. Accessed October 18, 2022.
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