Medical Marijuana for Moms-To-Be (Safe Cannabis Use While Pregnant)

CANNABIS CULTURE – Read any packet of medication, and you will often find words like “please ask your pharmacist and/or doctor before using this medication if you are pregnant.” This rule still absolutely applies to cannabis use. This is because even everyday over-the-counter drugs like ibuprofen (Advil, Motrin), naproxen (Aleve) and aspirin/acetylsalicylic acid (Aggrenox, Asprimox) can potentially harm the foetus. This is made even more complicated by the fact that even relatively safe and effective drug or medication can become potentially dangerous to both mother and/or child during pregnancy. Risk:benefit ratios change drastically when a woman is pregnant, even with otherwise nominally “safe” drugs. It is estimated that approximately 4% of women used cannabis during pregnancy.

To make matters even more complex still, there are ethical considerations to consider as well, such as “Is it right to test a drug on a pregnant woman, especially when we don’t know what sort of effect it will have?” Sadly, this means that many drugs aren’t researched effectively for safety and efficacy when it comes to pregnant women. There are also some instances when a drug or medication might be OK to use for the first trimester or two, but not in the third trimester. Now, when it’s hard to get even benign drugs that have been passed by the Food and Drug Administration (FDA) tested for pregnant women, imagine how hard it is for cannabis, where it is difficult to get funding for research even into non-life-threatening conditions.

Here’s a simple guide as to the general advice given to pregnant women as to what drugs are recommended (or not) during pregnanc.

Pain Medications

Acetaminophen (Tylenol, Paracetamol) – The pain reliever of choice for pregnant women.

Aspirin – Not recommended except for specific conditions.

Ibuprofen (Advil, Motrin) – Use with caution, preferably asking pharmacist/doctor before using it. Avoid use in third trimester.

Ketoprofen (Orudis) – Use with caution and avoid in third trimester.

Naproxen (Aleve) – Use with caution and avoid in third trimester.

Non-Selective Antihistamines, Expectorants and Decongestants

Chlorpheniramine (Chlor-Trimeton) – Antihistamine of choice.

Pseudoephedrine hydrochloride (Novafed) – Another antihistamine of choice, but there may be a small chance of gastroschisis (a birth defect where the baby’s organs are found outside of the body).

Guaifenesin (Humibid L.A.) – Possibly unsafe in the first trimester and beyond.

Dextromethorphan hydrobromide (Benylin DM) – Could be safe in pregnancy.

Diphenhydramine (Benadryl) – Possible oxytocin-like effects at high dosages, meaning it could potentially induce labor.

Clemastine fumarate (Tavist) – Safety profile unknown.

Antidiarrheal Agents

Kaolin and pectin (Kaopectate) – Antidiarrheal of choice.

Bismuth subsalicylate (Pepto Bismol) – Not recommended.

Loperamide/Loperamide hydrochloride (Imodium) – Possibly safe, but some complications may arise during first-trimester use.

Atropine/diphenoxylate (Lomotil) – Not recommended.

Antacid Preparations

Calcium carbonate (Tums) – Generally regarded as safe.

Simethicone (Mylanta Gas) – Generally regarded as safe.

Cimetidine (Tagamet) – Generally regarded as safe. Most commonly used if antacids don’t work.

Ranitidine (Zantac) – Generally regarded as safe. Most commonly used if antacids don’t work.

Nizatidine (Axid) – Not recommended.

Famotidine (Pepcid) – Could be safe, but more data is needed.


Butoconazole (Femstat) – Possibly safe.

Clotrimazole (Lotrimin) – Safe in the first and third trimesters; possibly safe in the third trimester.

Miconazole (Monistat) – Possibly safe.

Tioconazole (Vagistat-1) – No data.


So, as you can probably see, if even most relatively safe FDA-approved drugs are difficult to recommend for pregnant women, the complications grow exponentially when it comes to testing for the safety and efficacy of cannabis. Plus, safety and efficacy must be tested across the first, second and third trimester, and it would be especially difficult to recommend cannabis to someone in their second or third trimester.

“But wait a second. Many of these relatively safe drugs are more dangerous than cannabis when it comes to the chance of overdose and other negative side-effects. If cannabis is possibly safer for children than many pharmaceuticals, then why not for pregnant women as well?” Well, there is some sense behind this question, but it needs to be answered fairly and objectively.

First of all, taking away a child from their parents should they test positively for cannabinoid metabolites is something I cannot support, especially as cannabinoids tend to stick to the fat in the body and can be detectable for several months afterwards, even after usage has stopped. As for women who use cannabis during pregnancy, it’s a controversial issue. Just because cannabis is safer to use during pregnancy than many other pharmaceutical drugs and alcohol, it doesn’t mean there aren’t any dangers whatsoever.

There are several studies out there linking cannabis/marijuana use during pregnancy to impaired neurodevelopment in the child, lower birth weight, premature birth, behavioral problems and even stillbirth. Most pregnant women who use cannabis also seem to smoke it, which may potentially mean more carbon monoxide getting to the foetus. Again, this is all hypothetical and there is no definite evidence proving this, but it intuitively makes sense.

However, it’s too simplistic to say “Cannabis is definitely harmful to the foetus.” For a woman going through extreme morning sickness (hyperemesis gravidarum) and in need of relief, could some form of cannabinoid-based medication be of use? Why yes, of course! Yes, there are possible dangers, but these must be balanced against risk. We must also compare it with other treatment modalities.

Usually, in anything but the most extreme cases of morning sickness, treatment isn’t necessary and could potentially do more harm than good. However, for women with hyperemesis gravidarum (HG), severe weight loss and dehydration is a possibility, and hospitalization and treatment is often necessary. HG also doesn’t usually end at the 14-week period when morning sickness tends to go away, and may even persist after 20 weeks of pregnancy. This makes HG potentially dangerous.

Usually the treatment for HG is pyridoxine (a vitamin-B6 supplement), which is reasonably well-tolerated and is considered generally safe for expectant and breastfeeding mothers. Pyridoxine is often combined with the antihistamine doxylamine, and is generally considered safe for those who are pregnant. Side-effects can include drowziness, headaches and sleepiness. Ginger is also used, as it may reduce/block gastrointestinal (GI) signalling and thereby reducing nausea. These are likely to be the first go-to treatment methods for HG treatment, and are most likely the safest.

In other instances, several other drugs may be used, such as:

  • Metoclopramide (Reglan) – Generally safe, but as it’s a dopamine antagonist it is contraindicated for those on antipsychotics. May also cause headache, depression, hypertension, hypotension and sometimes even more extreme side-effects such as movement-based disorders (tardive dyskinesia, which is involuntary movement and is a result of dopamine receptor antagonism).
  • Promethazine (Phenergan) – Again, generally considered safe, but may cause fatigue, drowziness, dizziness and respiratory depression. Tardive dyskinesia is another side-effect and, in extreme cases, even epilepsy-like seizures.
  • Prochlorperazine (Compazine) – A potent antipsychotic and dopamine receptor agonist often used to treat vertigo, nausea and vomiting. As with all antipsychotic medications, there is the possibility of developing neuroleptic malignant syndrome (NMS), where symptoms include high fever, confusion, heart palpitations, high levels of potassium in the blood, variable blood pressure and further dehydration. Complications of NMS can include kidney failure and seizures. Treatment of NMS can include benzodiazepines (e.g. diazepam), which can cause further complications.
  • Trimethobenzamide (Tigan) – Generally considered safe, as trimethobenzamide does not affect the serotonergic or histaminergic systems, it doesn’t have the range of side-effects many other drugs have. However, trimethobenzamide is still a dopamine antagonist, and side-effects can include dizziness, drowziness, muscle cramps, blurred vision and fatigue.
  • Ondansetron (Zofran) – Unlike the above drugs, ondansetron is a serotonin agonist and doesn’t have any effect on the dopamine receptors. Ondansetron is a generally well-tolerated drug, but may cause constipation, diarrhea, dizziness, and headache.

Cannabis may work for HG in a similar way to why it may work for generalized nausea – THC and CBD are CB1 agonists that reduces the release of 5-HT and indirectly activates the serotonin receptor, 5-HT1A. However, dosage is key – using a little cannabis may help prevent nausea, but using too much might induce nausea. There are even some midwives who recommend using small amounts of cannabinoid-based medication during the first trimester of pregnancy to reduce anxiety and prevent morning sickness, but as THC can pass the placenta, it is sometimes used as a resort when other medications don’t work, or where other medications may have more serious side-effects.

So, what can we conclude about using medical marijuana for treating morning sickness? Well, all truth be told, sadly the answer is “Not much”. The fact is, we don’t know how THC and other cannabinoids affect the developing brain, and the statistics on expectant mothers who use cannabis may be complicated by use of other substances such as tobacco. Several studies show that there may be some increase in the likelihood of birth defects, but there is no definitive statistically significant proof that this is definitely the case. Some studies say that “Yes, cannabis is harmful to a developing foetus and may cause birth defects, as exposure to marijuana may cause changes in a foetus’s brain”, whilst others say that “it may have an effect on cognitive development several years down the line”. Others still say that the evidence is overall inconclusive. Due to the lack of research and the difficulty in researching drugs for pregnancy, I cannot say for sure that “cannabis is safe for an expectant mother”.

However, this is the case for cannabis as medicine for any condition, so we should not shut it off entirely as a potential antiemetic specifically for morning sickness. Also, much of the focus has been on THC – remember, pregnant women may be able to use CBD to beat nausea, with a low likelihood of any psychoactive effects. As for the harm CBD might cause to the foetus, this is again unknown, but intuitively it makes sense that CBD will not likely have any detrimental effect on a developing foetus, as it doesn’t have the psychoactive effects THC (or even many pharmaceuticals used for pregnant women) has.

Cannabis Culture Magazine

Cannabis Culture is an activist magazine dedicated to liberating marijuana, freeing pot-prisoners around the globe, and bringing an end to the vicious worldwide war on drugs.