Published in Modern Athletic Health

It’s controversial. It’s a topic that incites passion on both sides of the issue. So instead of adding fuel to the fire of conjecture, let’s take a hard look at whether utilizing cannabis during pregnancy is ever okay. So set your preconceived notions aside and let’s get our science on!

As of the writing of this article, twenty six states (and D.C.) have passed laws legalizing marijuana for medical use. Seven of of those states have also legalized the use of recreational marijuana. Amongst its many acclaimed benefits, cannabis is renowned for its calming and anxiety relieving benefits and ability to help reduce nausea, headaches, and panic attacks. It can also help improve sleep and create pleasant dreams. It’s probably clear at this point why pregnant women would consider using cannabis to help them get through 9 physically and emotionally trying months while they grow a tiny human and plan for their entire world to change.  

That sounds pretty excellent, right? I mean, man or woman, pregnant or not, who wouldn’t want to feel better, especially when you can do so with an all-natural substance? Well, there are several notable concerns. Tetrahydrocannabinol, or THC, is the active chemical component in cannabis affects many systems in the body and can create the “high” sensation. According to a study by Dr. Ernest L. Abel, a professor of obstetrics and gynecology at Wayne University, THC is known to pass, in the mother’s blood, through the placenta and to the fetus. Dr. Abel's observations made him concerned that this could cause low birth weight, birth defects, and stunted postnatal development.

In Dr. Abel’s study, mentioned previously, it is important to note that since it is unethical to do testing on expectant mothers, the information about the effects of THC on the placenta and fetus is sourced from clinical observation. He also notes that, while the prospect of cannabis passing its active ingredients to the fetus can be alarming, he felt it was important to point out that it can be very difficult to accurately evaluate clinical observations. He references two reports of birth defects in children who were born to women who used marijuana during pregnancy. However, as they were also using other narcotics, the results were actually inconclusive. Epidemiological studies following clinical observation can provide deeper insight into the effects of cannabis on the body, but unfortunately their scope is limited to observations noted during inspection. After many pages of explanation about placental transplant studies, animal testing, and other forms of examination and research, Dr. Abel concludes that “Prenatal exposure to cannabinoids does not produce gross malformations in humans.” He did observe that cannabis caused a fairly consistent reduced birth weight in animals, and other studies have shown similar effects in humans, but that there were no negative post-birth effects.

A study published in 2014 reviewed over 20,000 birth records and concluded that the rate of a certain neural tube defect which causes brain malformation nearly doubled (but was still incredibly rare) in babies born to women who used cannabis daily during pregnancy. Since these statistics are reliant on mothers honestly and accurately reporting their use of marijuana and other drugs during pregnancy, this study also took a look at the rate of underreporting defects. They concluded that, while there might be some underreporting for some of the clinical observations, the bias was “likely limited.” While this study seems deeply disconcerting, it would be unfair not to mention the fact that there have been many other studies that have found no direct connection between cannabis and birth defects. An important and therefore often quoted study is from the American Journal of Public Health in 1983. They studied over 12,000 women's medical records to try analyze the correlation between cannabis and birth defects. They did note an increased number of birth defects in the children of cannabis users compared to the statistical average, but when they included demographic aspects, inclinations, and medical history they concluded that the connection was not statistically significant.

In 1991, a study of a five-year follow up on rural Jamaican women was published in the West Indian Medical Journal. The study was relatively small, assessing 59 children starting at infancy and going through to five years old. The study compared the development and temperament over the years of the children of women who used cannabis during pregnancy to those of children from women who did not use cannabis. Researchers concluded that there was no difference between the two groups of children except that, at 30 days of age, the children of users tested better in both stability and reflexes. By ages four and five, they found differences in development correlated much more closely to home environment and school attendance than to the mothers using of cannabis.

However, a 2011 Australian study of over 24,000 women concluded that children born to women who use cannabis may be underweight, have a shorter gestational period, and be more likely to end up in the NICU after birth. However, they also commented that these results could be confused by maternal factors such as the mother's weight, alcohol consumption, diet, lifestyle, and whether or not she smokes cigarettes.

While really digging into mountains of research for this article, I read dozens of studies that stated one negative effect of cannabis or another on pregnancy, but a very high percentage of them ended with the same caveat, somewhere along the lines of “while marijuana causes bad and dangerous stuff during pregnancy, it could be other contributing factors, too.” As a medical herbalist, this is a topic I get questioned about frequently. Well, that and if I sell pot (I do not, by the way). I often refer my clients to doctors who can prescribe medical cannabis, which is legal in Connecticut, for appropriate conditions, and am a firm believer in its healing properties. However, when you involve a tiny growing organism in the picture, things get more complicated. The best answer I can give to the question of whether cannabis is safe during pregnancy is an annoying three-part answer.

You have to weigh the risks. There are potential negative effects, but do those possibilities outweigh the reason you’re using? For instance, are you using cannabis for anxiety instead of taking prescription medication? How would that medication affect your pregnancy versus the cannabis? Could you succeed without any assistance? Only you, and your doctor, could answer those questions concretely.

If you choose to pursue the use of cannabis during pregnancy, or any time, medical grade is the way to go. Not only do you get the purity and quality needed for therapeutic applications (especially during pregnancy), but you avoid any lacing or other added concerns. Also, talk to an expert to make sure you are using the correct variety and amount for whatever condition you’re trying to address.

If you decide to use cannabis and have obtained the proper strain, quality, and quantity, consider finding an alternative way to consume it other than smoking. I personally and professionally do not recommend smoking anything during pregnancy. Cannabis can be used as a tea, a tincture, a salve, or baked into food. Again, talk to an expert about what is best for you.

My last piece of advice is not part of my three-part answer (since I already used all three). As with so many of those studies, conclusions, as important as the question of using cannabis during pregnancy, is ensuring that you are living an otherwise healthy life leading up to and during your pregnancy. Eat well, drink lots of water, exercise regularly, and keep stress low. Lots of studies show that high stress does in fact cause birth defects and complications, so sip some tea, check out mindfulness meditation, relax, and enjoy growing your tiny human!


These facts and opinions are those of a certified Master Herbalist, Reiki Master Teacher, and a Natural Health Consultant, and are for educational purposes only, and not intended to replace consult with your healthcare practitioner.
If you have any questions or concerns about anything in this article, please contact me or your natural healthcare practitioner immediately.