Pregnancy & breastfeeding

Woman with newborn and toddler

What you need to know about cannabis

The safest choice? Whether you're expecting or nursing, it's important to know how cannabis can affect your baby. While research is still ongoing, current studies show that cannabinoids can cross the placental barrier, meaning if you consume cannabis, so does your baby. It’s best to talk to your health provider if you're considering cannabis use during pregnancy or breastfeeding.

What research and science tell us

During pregnancy and breastfeeding, many people take extra care with their health choices to support their baby’s development. One area that can raise questions is cannabis use. While cannabis is legal in Canada, that doesn’t mean it’s risk-free—especially during this time. Cannabis smoke contains many of the same harmful chemicals found in tobacco smoke, and even second-hand exposure may pose risks. Although some studies may downplay the effects, Canadian health experts agree that avoiding cannabis during pregnancy and breastfeeding is the safest choice for both parent and baby.

 

Effects of cannabis use on pregnancy
Light green cannabis leaf

Your doctor knows best

Every pregnancy and parenting journey is unique and so is your health. While we can share general information, only a healthcare provider can give you advice that’s tailored to your specific needs. They can help you understand the latest research, weigh the risks, and explore safe alternatives if you're struggling with symptoms or cannabis use. When in doubt, start the conversation—it’s the best way to make informed, confident choices for you and your baby.

Common cannabis questions

We get it there’s a lot of conflicting information out there. Whether you're curious, concerned, or just want to make informed choices, here are some of the most frequently asked questions we hear about cannabis use during pregnancy and breastfeeding—answered through research-backed expert resources.

While smoking is known to be harmful to both mom and baby, it doesn’t necessarily mean that other methods of consuming cannabis are safe. No method is considered safe—THC and CBD can still reach your baby through the placenta or breastmilk. Higher potency products, like vapes, carry additional risks and deliver more THC to the baby and pregnant person.

Research shows that THC and CBD can pass from pregnant person to baby through the placenta during pregnancy. This means your baby is exposed to harmful chemicals that may affect their brain development. These changes may cause behavioural and/or mental health issues that may last through childhood and adolescence.

Studies suggest that using cannabis while expecting may be associated with low birth weight, pre-term labour, and stillbirth. In addition, babies born pre-mature, for any reason, often have more health concerns and need additional care, as opposed to babies born full-term. Check out this study which focuses on the effects of pre-mature birth to learn more.

It’s tough for researchers to track people from pregnancy all the way into adulthood to study the effects of cannabis. That’s why some studies use animals to explore possible risks. If you're curious, check out this evidence review to learn more.

Currently, cannabis is not recommended as a first line of treatment for any condition regardless of what you may have heard about how cannabis could be used to treat nausea and/or vomiting.

Morning sickness can vary person to person, pregnancy to pregnancy and in some cases be more severe for some. The medical term for severe nausea and vomiting during pregnancy is hyperemesis gravidarum and can become a more serious complication.

Regardless of the severity of morning sickness cannabis can cross through the placenta and affect fetal development. Until we have longer term evidence of pre-natal cannabis exposure, talk to your doctor or healthcare provider first about what options could work for you to treat your morning sickness. 

Yes. Studies show that cannabis may affect menstrual cycles, sperm count and quality and could impact overall fertility for both partners. It's something to consider for both men and women, not just during pregnancy but in the months leading up to it.

Cannabinoids are stored in fat cells throughout the body; this includes the fat in breast tissue. . Those fat cells store cannabinoids and leak them into the breastmilk as it is produced which passes cannabis from mom to baby while breastfeeding.  Pediatricians agree that breastfeeding is the healthiest option for babies, however, it is important to weigh the benefits against the potential risks of exposing your infant to cannabis. Talk to your doctor if you are struggling to balance your cannabis use while breastfeeding.  

Evidence suggests that cannabinoids introduced through breastmilk can have adverse short-term effects on infants, with symptoms including difficulties waking up and feeding poorly. Cannabis can remain in breastmilk for days to weeks after using, so if you do plan to use cannabis, it is important to find alternative ways of feeding your baby.

Studies have also found THC in the stools of babies after breastfeeding—indicating that babies absorb and metabolize cannabis from breastmilk. Therefore, small amounts of THC in breastmilk could potentially lead to brain developmental issues in babies. If you want to learn more about the effects of THC on nursing infants, read the “Breastfeeding” section of this research report.

Another good reason not use cannabis while breastfeeding or caring for an infant, it could be detrimental to a nursing mother's judgement and alertness. As such, you may not easily recognize important cues for hunger, comfort, playing or learning.

It’s understandable to want reassurance, but not all studies are created equal. Some online articles or studies may confirm what we hope to hear, but they might be based on small sample sizes, surveys, or lack rigorous scientific standards. A trustworthy study is well-designed, peer-reviewed, and published in a reputable journal. Even then, it’s important to look at the broader scientific consensus, not just one study. If a single study contradicts the majority of research, it may be flawed or not yet fully understood. Always consider the weight of evidence across multiple high-quality studies when making decisions about your health and your baby’s.

If you're struggling to quit

You're not alone. Reducing or quitting cannabis can be hard—especially if it's part of your routine. Talk to your doctor about support services that can help you and your partner make the healthiest choice for your baby.  After you've spoken with your doctor and if you choose to continue your cannabis use, visit this site for more tips.

Light green cannabis leaf

Alcohol and pregnancy

Cannabis and other drugs, like alcohol is strongly advised to be avoided during pregnancy and breastfeeding. There is no known safe amount of alcohol during these stages, and even small amounts can affect your baby’s development. To support Albertans in making healthy choices, the Dry9 program encourages going alcohol-free for nine months of pregnancy. Over 9,000 Albertans have already joined the movement. Learn more, sign up, or support someone doing a Dry9 at Dry9.ca.

Learn more

Want to dive deeper? These trusted resources offer up-to-date, medically reviewed information about cannabis use during pregnancy and breastfeeding. Whether you're looking for research, support, or expert guidance, these sites are a great place to start:

Alberta Health Services DrugSafe

Government of Canada—Cannabis in Canada, Get the facts

Health Canada—Is cannabis safe during preconception, pregnancy and breastfeeding?

Ready or Not Alberta

The Society of Obstetricians and Gynaecologists of Canada

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