What We Know About Cannabis Use in Pregnancy and Breastfeeding

I have spent the last two decades as a birth worker, doula trainer, and labor & delivery and maternal child health nurse.  I have been able to support families from prenatal education and yoga, labor and delivery, to watching children and families grow in so many directions.  I have been hearing the same question tossed around the birthing world for years, and it continues to be a hot and controversial topic.  Cannabis use in pregnancy and breastfeeding?

Cannabis as medicine for females and the female reproductive tract is recorded as early as 2737 BCE, for migraines, moon/menses cramps, discomforts of childbirth, and even to induce labor.  From the 19th century to the early 20th century, Cannabis was a common ingredient in pharmaceutical apothecary remedies specifically for women.  Today, about 9.5% of childbearing aged women report cannabis use within the last month.  Cannabis use is most prevalent in women aged 18– 25 and has increased in use over the last decade.  Pregnant women report decreased use in pregnancy and less cannabis use (7% overall) compared with non-pregnant women.

So, what do we know?  Unfortunately, not as much as we would think or hope to know.  The limited amount of information in this area is not drastically different from the limited available information in most other areas with cannabis and is the result of being a Schedule I controlled substance.  This means that it has “no currently accepted medical use in treatment in the United States, a lack of accepted safety for use under medical supervision, and a high potential for abuse.”  The Drug Enforcement Administration (DEA) regulates cannabis research, hence making the drug difficult to study.

Varying statistics show that at least 7 out of 10 pregnancies include the mother taking some sort of medication.  Associated medication risks and concerns is another area we lack much needed information on, due to the safety and ethical concerns around research in pregnancy and  breastfeeding.  This lack of information, yet clear need for medication in many pregnancies, leaves a gap in evidence-based resources and care; and has families deciphering what to do before they are able to make the hard decision as to medicate or not.

For perinatal mood disorders and patients, this can be a very challenging topic as most mental health and psychiatric pharmaceuticals are in the FDA category C, meaning again we do not know for sure the associated risks.

Data has not identified any long-term or long-lasting meaningful differences between children exposed in utero to cannabis and those who are not.  We do know the endocannabinoid system is present early in fetal development.  Cannabinoids are able to cross the placenta.  So, there is a concern about exogenous maternal cannabis use during pregnancy and whether it may interfere with fetal brain growth and neurodevelopment.  Hence, there is a theoretical potential for maternal cannabis use in pregnancy to interfere with fetal neurodevelopment.  The limited research available focuses more on  centering tetrahydrocannabinol (THC than CBD cannabidiol).

With prenatal neonatal exposure to cannabis, available research has shown concern of low birth weight and increased risk of Neonatal Intensive Care Unit (NICU) admission as well as pregnancy complications.  The studies available do not take into account needed information on several confounding factors including other illicit and licit medications and substances, such as nicotine and pharmaceuticals.

Even less information is available on CBD, as limited studies do show some concern for placental permeability while promising interaction with reducing uterine contractions.  CBD has shown promising results in animal studies showing that the cannabinoid works as an antidepressant and anxiolytic, which makes me wonder if this may be a positive alternative to other pharmaceuticals with increased risk and concerns.

We do know cannabinoids, such as tetrahydrocannabinol (THC) and cannabinol (CBD), simply put, like to stick to fat, which is abundant in human milk, suggesting that those compounds can and may end up in human milk.  Without the proper research, the health risks to these infants largely remain undetermined.  The World Health Organization used data from 1982 for some of their statements and positions.  Long-term information and outcomes after maternal cannabis use during breastfeeding are needed.  More research will ultimately be possible and available for a more accurate understanding if cannabis is reclassified and off the schedule one status.

Researchers at the Centers for Disease Control and Prevention recently developed a promising and exciting method for analysis that begins with saponification.  The test is mentioned to be 100 times better at detecting THC (and cannabidiol) in milk than previous techniques, so we are making progress.

A recent study of 50 women, utilizing this method, showed that (Δ-9-tetrahydrocannabinol )THC was measurable in 63% of milk samples, up to 6 days after last use; CBD (cannabidiol) was measurable in 9% of milk samples, and cannabinol was undetectable in all samples.

I was at the Vermont Lactation Consultants Annual Conference in 2014 and was part of the “Surveying Lactation Professionals Regarding Marijuana Use and Breastfeeding” with the University of Vermont (UVM).  We were given the opportunity to complete a five-item survey.  74 of 120 attendees completed the survey.  44% reported their recommendations around breastfeeding and marijuana use depended on multiple factors, severity of maternal use being number one.  Another 41% reported recommending continued breastfeeding with cannabis use because the benefits outweigh the harms.  The remaining 15% reported recommending that a woman should stop breastfeeding if she cannot stop using marijuana.  Survey participants estimated that 15% of their breastfeeding clients in the past year used marijuana.  It was concluded that lactation professionals vary widely in their recommendations to breastfeeding clients who use marijuana.  The estimate of prevalence also suggests this is a relatively common issue.  Again, Vermont determined more research is needed.

I now work as a nurse in research at UVM, will be speaking on opioids and cannabis in pregnancy and breastfeeding at this year’s Vermont Lactation Consultants Annual Conference and have just been granted permission to continue and repeat this same study, five years later and six months after Vermont legalized recreational cannabis use.  More information to come!

Regardless of the limited evidence-based research, like the majority of Vermont lactation consultants, many health care providers and birth workers still believe that the benefits of breastfeeding outweigh the possible risks of cannabinoids being present in human milk.  Of course, it is recommended that one abstain or at the least reduce cannabis use as much as possible and always avoid any infant exposure to second and third hand smoke.  Cannabis microdosing is becoming more popular and helps people use the least amount of cannabis needed.

All said and done, no one can make the decision for you and your family but you.  Do your benefits outweigh the associated known, or hypothesized, risks?  Do you have a care provider you can be open with and talk to about your cannabis use?  Do you have a cannabis medical professional you can talk to for more information?

If one were to choose to use cannabis, my number one recommendation is that it is grown and processed organically.  Look for transparency in lab testing and reputable companies.  Many states do not have regulations, so until they do, it is up to a consumer to understand and learn what is best.  This can be daunting in and of itself.

Again, the general and overall consensus is that there is not enough evidence-based research for medical professionals to make any recommendation or informed decision other than discouraging use in pregnancy and breastfeeding.

American Society of Addiction Medicine

“Data are sufficient to suggest that . . . pregnant women . . . should not use cannabis or cannabinoids due to a variety of neuropsychiatric health effects and impacts on cognitive functioning.”

American College of Obstetricians and Gynecologists

“Women who are pregnant or contemplating pregnancy should be encouraged to discontinue marijuana use.”

“There are insufficient data to evaluate the effects of marijuana use on infants during lactation and breastfeeding, and in the absence of such data, marijuana use is discouraged.”

American Academy of Pediatrics 

“Cannabis can be detected in human milk, and . . . use by breastfeeding mothers is of concern, particularly with regard to the infant’s long-term neurobehavioral development and thus are contraindicated.”

The Academy of Breastfeeding Medicine

“A recommendation of abstaining from any marijuana use is warranted.  At this time, although the data are not strong enough to recommend not breastfeeding with any marijuana use, we urge caution.”

The Academy of Breastfeeding Medicine acknowledges the presence of conflicting data and currently recommends lactating mothers to decrease or completely stop marijuana consumption due to the potential neurobehavioral consequences of prolonged exposure to the child. The Academy also encourages lactating mothers to be cautious if using cannabis, as there is inadequate evidence to support the discontinuation of breastfeeding.

Hale’s 2012 Medications and Mother’s Milk placed cannabis in the highest risk category, L5 or Hazardous, the criteria for which include the statement ‘‘using the drug in breastfeeding women clearly outweighs any possible benefit from breastfeeding’’.  His most recent publication MMM has changed that stance from a L5 to L4, making cannabis use no longer contraindicated in breastfeeding.

One last thing before I close that I want families to be aware of.  A positive urine drug screen result in pregnancy or infancy could have different and possibly negative legal implications in some states.  For all mandated reporters, reporting cannabis use is still considered appropriate but again may have varying legal and ethical implications.  In Vermont, law has recently shifted.  As of November 1, 2017, having a positive THC urine drug screen in pregnancy or infancy is not alone a reason to open an investigation with protective services.  This is an enormous change to the social services and mandated reporting systems that went unannounced.  Please learn your state laws to be able to be the best advocate and support for your clients.  Please reach out to an experienced medical professional for more information and individualized support or email me at greennursevt@gmail.com.

Bibliography & Further Study

  • Anderson, P. (2017). Cannabis and breastfeeding. Breastfeeding Medicine, 12(10), 580-581.
  • Baker, T., Datta, P., Rewers-Felkins, K., Thompson, H., Kallem, R.R., Hale, T.W. (2018). Transfer of inhaled cannabis into human breastmilk. Obstetrics & Gynecology, 131(5), 783-788.
  • Bergeria, C.L., Heil, S.H. (2015). Surveying lactation professionals regarding marijuana use and breastfeeding. Breastfeeding Medicine, 10(7), 377-380.
  • Dreher, M.C., Nugent, K., Hudgins, R. (1994). Prenatal marijuana exposure and neonatal outcomes in Jamaica: An ethnographic study. Pediatrics, 93(2), 254-260.
  • Foeller, M.E., Lyell, D.J. (2017). Marijuana use in pregnancy: Concerns in an evolving era. Journal of Midwifery & Women’s Health, 62 (3), 363-367.
  • Mark, K., Terplan, M. (2017). Cannabis and pregnancy: Maternal child health implications during a period of drug policy liberalization. Preventive Medicine, 104, 46-49.
  • Metz, T.D., Stickrath, E.H. (2015). Marijuana use in pregnancy and lactation: A review of the evidence. American Journal of Obstetrics & Gynecology, 213(6), 761-778.
  • Mourh, J., Rowe, H. (2017). Marijuana and breastfeeding: Applicability of the current literature to clinical practice. Breastfeeding Medicine, 12(10), 582-596.
  • Obstetrics & Gynecology (2017). Committee opinion No. 722 summary: Marijuana use during pregnancy and lactation. Obstetrics & Gynecology, 130(4), 931-932.
  • Passey, M.E., Sanson-Fisher, R.W., D’Este, C.A., Stirling, J.M. (2014). Tobacco, alcohol, and cannabis use during pregnancy: Clustering of risks. Drug and Alcohol Dependence, 134, 44-50.
  • Russo, E. (2002). Cannabis treatments in obstetrics and gynecology: A historical review. Journal of Cannabis Therapeutics, 2(3-4), 5-35.
  • Wilson, L. (2016). Breastfeeding and marijuana use: The endocannabinoid system. Retrieved from https://www.youtube.com/watch?v=NJwd8dlqoco.
  • Worstell, T., Gorman, M., Caughey, A. (2015). 233: Cannabis in pregnancy: legal, but safe? American Journal of Obstetrics & Gynecology, 212(1), S129.

Jessilyn Dolan

RN, CLD, CAPPA FACULTY

Jessilyn Dolan has been working with birthing families for over ten years. She is a registered nurse and certified massage therapist, specializing in maternity and deep tissue massage, acupressure, reiki, and craniosacral therapy. Jessilyn is a certified Labor Doula, Certified HypnoBirthing Childbirth Educator and Certified Infant Massage Instructor. She is chapter leader of Vermont’s first ICAN. Jessilyn previously owned and operated a Family Wellness Center for five years, incorporating all of her birthing knowledge and classes and instructing yoga for all ages. She previously taught Reflexology, Anatomy and Physiology and Traditional Chinese Medicine classes in the massage program at the Community College of Vermont. Jessilyn has worked at shelters with victims of domestic and sexual violence and families with diverse backgrounds and special needs. She is a caring, honest, and open woman who wants to help make a difference in the lives of those around her. Jessilyn lives in the northern woods of Vermont with her family, a house full of boys!

1 thought on “What We Know About Cannabis Use in Pregnancy and Breastfeeding”

  1. jennifer Kendrick

    Jessilyn,
    You made a very profound statement, ” The studies available do not take into account needed information on several confounding factors including other illicit and licit medications and substances, such as nicotine and pharmaceuticals”.
    I wonder if you have any statistics on the number of contaminants that marijuana is often mixed with that can also pose potential harm to the developing fetus.
    I wonder too, about not only the neurodevelopmental, but about fetal reserve and tolerance of the hypoxia that contractions present. If mom uses and experiences respiratory depression, vasoconstriction (both common effects) or God forbid, pneumothorax – is she risking depleting oxygenation to her baby, affecting for more than just neurodevelopment?
    Just thoughts…..

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