Medical Marijuana in Pregnancy

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Marijuana is one of the most popular recreational drugs in the United States and, in recent years, its use has been decriminalized in many states.1 Currently, the use of at least some forms of marijuana is legal in most states.2,3 (All marijuana use is still illegal under federal law.2,4) Owing to these changes in legal status, the use of marijuana is on the rise, and even the number of pregnant women who are using marijuana has increased.5-8 Its availability and legitimacy are leading to questions about its safety and benefits during pregnancy.9 We don’t know everything there is to know about marijuana and pregnancy, but read on to find out what we do know so you can make informed decisions for yourself and your baby.

What’s in it

Marijuana is a mixture of dried flowers of the cannabis plant, also called hemp. It can be rolled into cigarettes or cigar wraps, smoked in water pipes, brewed to a tea, and consumed in foods.10 Hundreds of chemicals called cannabinoids are found in marijuana. THC is the main mind-altering chemical in marijuana.10,11 THC causes the “high” associated with marijuana use and affects how you feel and how your brain works, even changing the way you see, hear, and feel things.3 THC crosses into the placenta and enters the bloodstream of a fetus.12

Cannabidiol (CBD) is the second most prevalent chemical found in cannabis and is the essential component of medical marijuana. By itself, CBD does not cause a “high” and it is not associated with abuse or dependence.11 CBD is becoming widely available and is increasingly used to treat epilepsy and seizure disorders, pain, anxiety and post-traumatic stress, Crohn’s disease, and multiple sclerosis.13

How it works

In the body, cannabinoids act at receptors within the endocannabinoid system (ECS). The ECS is located throughout the nervous system and is involved in many biological processes, including fertility, pregnancy, appetite, pain, mood, and memory. The human body naturally contains compounds that act in the ECS (called endocannabinoids) to regulate physical and cognitive functions. When you use marijuana, THC, CBD, and other cannabinoids that are not normally inside your body mimic endocannabinoids, act at the ECS, and promote changes in pain sensation, appetite, thinking, mood, etc.14,15

Who’s using it

A recent study published in the Journal of the American Medical Association (JAMA) reported that, in 2017, 7% of pregnant women reported using marijuana in the previous month. Use during the first trimester of pregnancy was higher at 12.1%. (This figure is more than double that of 15 years earlier.) More than 3% of pregnant women reported using marijuana daily or near daily.5,8

The JAMA study included both medical and non-medical uses of marijuana in its calculations, but only 0.5% of marijuana use was attributed to a medical use.5,6,8 Some states have legalized the use of marijuana during pregnancy to decrease nausea and vomiting, but it appears that healthcare providers are not recommending it to patients for this purpose.5 Currently, marijuana is not approved by the Food and Drug Administration for prevention or treatment of nausea and vomiting, and plenty of other options are available to help with nausea and vomiting during pregnancy.3,4

Who it can harm

The American College of Obstetricians and Gynecologists recommend that pregnant women, and even those trying to get pregnant, not use marijuana at all. It can negatively impact the mother’s health and, though research is limited about its effects on unborn babies, marijuana is associated with a risk of low birthweight, stillbirth, and preterm birth (read more here). Research also indicates that marijuana exposure can lead to abnormal brain development of a fetus and that children whose mothers used marijuana during pregnancy may have learning and behavioral issues later in life. Even secondhand smoke from marijuana is harmful to young children. 3,4,7,9,16

Marijuana use can cause clumsiness, dizziness, poor coordination, and trouble thinking clearly. Together, these symptoms can increase the risk of falls and make mothers less likely to care for themselves and their unborn babies.3

Who can help

Even though data that describe the effects of marijuana on unborn babies are limited, no amount of marijuana use during pregnancy has been shown to be safe. However, more research is needed before we will know the actual risks and benefits of marijuana use during pregnancy.3,16,17

Tell your healthcare provider if you use or are planning to use marijuana while you are pregnant. If you use marijuana and are trying to quit, resources are available from your doctor or from the Substance Abuse and Mental Health Services Administration ( or 800-662-HELP.)4


  1. Mumford S, et al. Preconception marijuana use and pregnancy outcomes (P-18-033-19). Curr Dev Nutr. 2019;3(Suppl 1).
  2. State marijuana laws in 2019 map.
  3. March of Dimes. Marijuana and pregnancy.
  4. American College of Obstetricians and Gynecologists. Marijuana and pregnancy.
  5. Lardieri A. Increasing number of pregnant women use marijuana, especially in first trimester. U.S. News. June 20, 2019.
  6. Volkow ND, et al. Self-reported medical and nonmedical cannabis use among pregnant women in the United States. JAMA. June 18, 2019.
  7. Committee on Obstetric Practice. Committee Opinion No. 722: Marijuana use during pregnancy and lactation. Obstet Gynecol. 2017;130(4):e205-9.
  8. Corsi DJ, et al. Association between self-reported prenatal cannabis use and maternal, perinatal, and neonatal outcomes. JAMA. June 18, 2019.
  9. Foeller ME, et al. Marijuana use in pregnancy: concerns in an evolving era. J Midwifery Womens Health. 2017;62(3):363-7.
  10. National Institute on Drug Abuse. What is marijuana?
  11. Grinspoon P. Cannabidiol (CBD) – what we know and what we don’t. Augst 24, 2018.
  12. Peters A. Consuming cannabis suring pregnancy: here’s what the science says.
  13. Cannabidiol.
  14. Human endocannabinoid system. UCLA Health.
  15. The science of the endocannabinoid system: how THC affects the brain and body.
  16. Young R, Paris F. Cannabis use doubles among pregnant women in the U.S., study finds. Here & Now.
  17. El Marroun H, et al. AN epidemiological, developmental and clinical overview of cannabis use during pregnancy. Prev Med. 2018;116:1-5.
Jennifer Gibson
Dr. Jennifer Gibson earned a Bachelor of Science degree in Biochemistry from Clemson University and a Doctor of Pharmacy degree from the Medical College of Virginia School of Pharmacy at Virginia Commonwealth University. She trained as a hospital pharmacist and is the author of clinical textbooks, peer-reviewed journal articles, and continuing education programs for the medical community, as well as a contributor to award-winning healthcare blogs and websites. In her free time, she enjoys running, reading, traveling, and spending time with her family.

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