The parts of the female cannabis plant that produce the majority of its magical, healing cannabinoids, the pistil, and calyx, are in fact that plant’s female reproductive organs. Ironically, those same crystals may not be such a godsend when it comes to human female reproduction. Or are they? The answer is not crystal clear.

Cannabis has recently become a well-known and accepted treatment for menstrual cramps. A bevy of new products on the market aim to ease women’s monthly suffering with cannabinoids. But when it comes to pregnancy and breastfeeding, using medical cannabis is a more controversial and less acceptable treatment.

Recently, the Washington State Liquor and Cannabis Board (WSLCB) mandated cannabis retailers post signage warning of the risks of using cannabis while pregnant or breastfeeding.

This isn’t surprising. There’s a long list of things women can’t do when pregnant and breastfeeding. Pregnant women can’t have alcohol, lunch meat, sushi, mold-ripened cheeses, ibuprofen in the final days, and cannabis, among other things. Breastfeeding women shouldn’t drink heavily, smoke, and have to be careful about which medications they take.

Pregnancy, Medicine, and the Lack of Answers

When it comes to over the counter and prescription medicine, the medical community isn’t so quick to draw a hard line. Studies often advise pregnant women to continue suboxone treatment, for example, despite a lack of solid data on whether or not it’s safe. Same goes for Selective serotonin reuptake inhibitors or SSRIs. The implication of the data from the studies on these medicines seems to be that these medications are either too unsafe to stop taking during pregnancy, or the outcomes of the addicted or depressed mothers would be worse should they discontinue use.

The fact is, doctors and scientists don’t know if many medicines are truly safe for pregnant women. That’s because pregnant women are rarely included in clinical trials for over the counter, or prescription drugs. The inclusion of pregnant women in clinical trials is a separate and complicated issue.

The FDA’s guidelines for including pregnant women in clinical trials is still in draft form. The eleven-page document is titled, “Pregnant Women: Scientific and Ethical Considerations for Inclusion in Clinical Trials Guidance for Industry.” The substantial ethical and legal dilemmas that doctors and scientists face including pregnant women in clinical trials, often means that they simply don’t include them. The knowledge available regarding the safety of medicine for pregnant women is largely based on data collected from pregnant women who used medicine in an uncontrolled, non-clinical setting.

Cannabis and Pregnancy: The Science

This is true for cannabis as well. There has never been a clinical trial for cannabis and pregnancy, as it would be illegal. The University of Washington is looking to conduct a study on pregnancy and cannabis, though not a clinical trial, it would still be the first of its kind.

The study, titled “Moms + Marijuana” is co-led by Drs. Natalia Kleinhans and Stephen Dager, radiologists at the University of Washington School of Medicine.

“The very few investigations that have studied prenatal cannabis exposure and infant brain development have all involved women who are polysubstance drug users. No one has looked at marijuana use exclusively,” Dr. Natalia Kleinhans said in a press release. “This study will also involve periodic drug testing during pregnancy to verify in real-time that moms aren’t using other drugs, rather than relying on the mother’s self-report after the child is born.”

The study is still in the recruitment phase and hopes to recruit 70 women who are in their first trimester of pregnancy. Of the 70 women, 35 would act as the control group, abstaining from cannabis, alcohol, tobacco, and other street drugs, and 35 would use cannabis to help with morning sickness at least twice a week while abstaining from all other drugs, tobacco, and alcohol.

“There’s little research to back up the medical and public health advice they’re getting to stay away from pot to control nausea,” Kleinhans stated. “Most medications prescribed for morning sickness have not been rigorously tested in pregnant women and appear to have side effects that are not minor. Pregnant women have minimal drug-safety information to rely on when deciding whether to take a pharmaceutical, but it’s marijuana that has the negative connotation.”

Despite the lack of evidence, some researchers are confident that women should absolutely abstain from cannabis during pregnancy.

One of these researchers, is Daniel Corsi, author of “Association Between Self-reported Prenatal Cannabis Use and Maternal, Perinatal, and Neonatal Outcomes“

“Currently there is a lack of evidence on the safety of cannabis in pregnancy. Many women are using cannabis in pregnancy to manage symptoms such as nausea and vomiting, pain, and for other reasons,” Corsi told The Sesh Seattle. “There is growing social acceptability for cannabis and many believe including from social media that cannabis is a low-risk activity in pregnancy.”

The study, which collected self-reported data from 661,617 pregnancies with 9,427 reported cannabis users, found that the rate of preterm birth among reported cannabis users was 12% versus 6% of the controlled group who didn’t use cannabis. The study did include women who used cannabis along with alcohol, tobacco, and prescription and street drugs, and women who used cannabis exclusively. Interestingly, the study also found that after adjusting for tobacco use, the use of cannabis independently was not associated with low birth weight or preterm delivery.

Despite the fact that adjusting for tobacco use seemed to negate the major finding of increased likelihood of low birth weight or preterm birth, Corsi told The Sesh Seattle, “In our study we found that there were some risks to the baby associated with use of cannabis during pregnancy including premature birth, increased likelihood of admission to intensive care nursery, and small size at birth.”

So when it comes to cannabis as an effective treatment for morning sickness, or other issues pregnant women face, there really isn’t any conclusive data to say it’s more or less safe than other drugs pregnant women are prescribed.

Cannabis and Breastfeeding According to Experts

But what about cannabis and breastfeeding? The answer: also murky.

Renee Beebe, a Seattle-based International Board Certified Lactation Consultant (IBCLC), spoke with The Sesh Seattle about the risks of using cannabis while breastfeeding.



“I attend every lecture, read everything I can find and talk to experts directly whenever I have the chance and I keep hearing the same thing—the bottom line is, at this point, we just don’t know,” Beebe said. “We know that THC is stored in fat, and milk is synthesized from fat. So if a breastfeeding person is using cannabis, it follows that there will be THC in their breastmilk. But there isn’t enough data to conclude how this affects the infant or for how long it remains in the milk.”

One issue Beebe brought up is the lack of effective oversight when it comes to cannabis products. High levels of pesticides​, fertilizers,​ and solvents in cannabis products could potentially be as or more harmful to infants than THC.

Beebe also stated, that at present with the science available, most lactation experts agree that, even with THC present in breastmilk, breastfeeding is still healthier for a baby than formula.

To further understand the complicated issue of cannabis and breastfeeding, The Sesh Seattle went to the man who wrote the book on drugs and breastfeeding, literally. Dr. Thomas Hale authored Medication and Mothers’ Milk, which includes information on breastfeeding and cannabis use and also authored the study, “Transfer of Inhaled Cannabis Into Human Breast Milk,” in the April 2018 issue of Obstetrics and Gynecology.

“The use of cannabis during breastfeeding should be minimized,” Dr. Hale told The Sesh Seattle. “It’s apparent from my study, that the amount in milk is low (about 2.5% of the maternal dose), and the amount absorbed orally in infants is low as well, perhaps less than 5% orally. So you can see the real dose the infant is exposed to is probably very low. However, this largely depends on HOW MUCH the mom smokes. We think, but don’t have the data yet, that really heavy users may put a lot of THC in their milk, and the exposure to the infant is greater.”

When asked about whether or not breastmilk with THC is preferable to formula feeding, Dr. Hale responded with some fascinating information.

“The [question of] relative risk is really important,” Hale stated. “Right now, many hospitals ban the use of moms’ milk when mom is drug screened positive for cannabis. But what do you do with premature infants, whose mother’s milk is a fabulous lifesaver? We know that breastfeeding reduces the risk of Necrotizing enterocolitis– a huge killer of premature infants, in premies by 14 fold, and it lowers the risk of GI infections as well. But some hospitals won’t let these moms breastfeed because they were drug screen positive for cannabis.”

Dr. Hale concludes, “The relative risk of THC in milk is negligible, compared to the life-threatening risk associated with formula feeding in a premature infant. Neonatologists all over the U.S. are now waging this battle against hospital policy and lifesaving policies with human milk. So we need to always weigh the relative risk of cannabis with the sometimes enormous risk of NOT breastfeeding.”

While Dr. Hale only referred to premature infants in his statement, basically all available science points to the fact that breastfed babies have better health outcomes than babies who are formula-fed. So the relative risk of cannabis, versus the known health risks of formula feeding even a healthy baby, should be considered as well.

Breastfeeding women, like pregnant women, are often not included in clinical trials for any drugs. So to say that cannabis is more or less risky to use while breastfeeding than other medications, is somewhat of a misnomer.

The Conclusion on Cannabis, Pregnancy, and Breastfeeding

Like basically everything when it comes to women’s health, this is a subject that comes down to choice. Personal feelings aside, recreational cannabis use during pregnancy and breastfeeding, regardless of the lack of conclusive science, is an unnecessary risk.

When it comes to medical cannabis, however, it’s odd that it’s considered conclusively unsafe, while other medicines with unknown effects are deemed safe enough for use. With all of the things, new moms have to feel guilty and scared about, we should learn more before resolutely adding medical cannabis to the list.