Intro:
The rising acceptance of cannabis use is raising questions in countries where legalisation is an ever-increasing phenomenon, especially in the United States, Canada, and the United Kingdom. It is important that both mothers-to-be and health care providers understand the cannabis risk to mothers and infants during pregnancy. Recent studies suggest that exposure to cannabis prenatally may be associated with adverse effects on the mother and fetus, and the understanding may be clouded by ideas about cannabis being a safe drug for use during pregnancy. Even a expectant mother using cannabis in modest amounts to help alleviate nausea, stress, or pain will ultimately present a risk, at least with respect to neurodevelopment outcomes for the infant. This article synthesizers scientific findings, international perspectives, and recommendations from leading experts about the safety of cannabis use in pregnancy.
Table of Contents
How Cannabis Affects Pregnancy
Influences on the Development of the Baby
The psychoactive agent in marijuana, THC, can cross the placenta to be present in the developing fetus. Prenatal marijuana exposure has been linked to important disruptions of brain development in utero, resulting in subsequent, more permanent cognitive and behavioural issues. Research indicates correlations between maternal marijuana use and deficits in memory, attention, and executive functioning and problem solving skills in children (if these studies are really comparing children prenatal marijuana exposure as opposed to other substances).
Risks for Low Birth Weight and Pre-Term Labor
Several studies also indicate that maternal marijuana use may increase the likelihood of low birth weight and preterm labor. Infants born with low birth weight or preterm are at heightened risk for cognitive disabilities, chronic health issues, and infection. In the limited research, the risk appears to be dose dependent-increased frequency of use results in larger negative impacts.
Neuro Developmental Effects in Children
Research on subjects over longer periods of time suggests that children exposed to cannabis in utero may have behavioural and emotional concerns such as hyperactivity and impulsivity and an increased risk of anxiety. This is of particular concern for brain development during the first trimester when the brain undergoes significant growth and differentiation.
Maternal Health Risks
The Use of Cannabis and Risk of Accidental Problems in Pregnancy
Mother’s use of cannabis is associated with a greater risk of accidental issues in pregnancy, including placental abruption, gestational hypertension, and preeclampsia, all of which may adversely affect maternal and fetal health. Thus avoidance of cannabis during pregnancy is recommended.
The Use of Cannabis and Risk of Miscarriage and Stillbirth
A small amount of developing evidence suggests that mothers who use cannabis may be at an increased risk of miscarriage and stillbirth. While the evidence is still developing, the majority of health-care professionals recommend for mothers to abstain from using cannabis to minimise risks to the pregnancy and protect the fetus.
Scientific Studies and Evidence
Research on cannabis risks in pregnancy investigates possible risks and limitations in particular studies. Various observational studies have consistently observed links between maternal cannabis use and adverse pregnancy outcomes such as low birth weight, preterm birth, and neurodevelopmental delays. Comparable findings have been established in animal research, which showed that prenatal THC induces structural and functional alterations in the brain.
Current studies have limitations as well, such as reliance on self-reported cannabis use, differences in potencies, and co-use with substances such as tobacco and alcohol. There are studies in progress to examine the impact of cannabis consumption over the long-term and determine safe limits (if any) of exposure in pregnancy.
Cannabis Types and Potency
Differences in Risk for THC Compared to CBD during Pregnancy
Cannabis contains many compounds, but the two active compounds are THC and CBD. THC is psychoactive, and nearly all of the harmful side effects associated with cannabis use during pregnancy have been linked to THC. CBD appears to not be psychoactive, but there has not been much research done to ascertain safety for pregnant people. Because the evidence is limited, professionals have recommended avoiding THC and CBD while pregnant.
Methods of Consumption: Smoking, Edibles, and Vaping
The way cannabis is taken can also change risk. Similarly, a primary method to use cannabis is smoking, which exposes the mother and fetus to harmful poisons and carbon monoxide. These substances in the body have the potential to lead to low birth weight and harm during pregnancy. While the amount of harmful toxins when vaping or taking edibles is significantly less, the use of THC in either method does still take the form of administration to the mother’s systemic system, and can cause harmful side effects to maternal function and fetal neurodevelopment and health.
Legal and Social Considerations
The legal status of cannabis varies globally, influencing use and stigma. For example, when looking at the United States and Canada, both have legalized cannabis for recreational and/or medical use, which arguably results in an increased prevalence of cannabis exposure among pregnant patients. Conversely, there are some countries in Europe and Asia that continue to outlaw cannabis completely, thus influencing the reporting of, and access to care, regarding the guidance of cannabis use.
Healthcare providers will repeatedly reinforce, that with or without legalisation, there will be no difference in the risk of exposure to cannabis as it relates to pregnancy, despite cannabis being illegal in certain jurisdictions. Thus, it is essential that women living in any jurisdiction receive adequate education and the ability to speak with their providers regarding exposure while pregnant, in order to reduce exposure and maximise successful pregnancies.
Expert Opinions and Recommendations
Experts believe that pregnant people should not use cannabis, a recommendation made by both obstetricians and pediatricians, who state “There is no known safe dose of cannabis for a fetus.” They give this advice from trusted organizations, but also cite possible neurodevelopmental implications for the offspring, possible low birth weight implications, and pregnancy conditions from the World Health Organization (WHO), the Centers for Disease Control and Prevention (CDC), and the American College of Obstetricians and Gynecologists (ACOG).
Other countries around the world share this recommendation. In the UK, the National Health Service (NHS) is an example of an organisation that similarly recommends no use, stating to protect both fetal and maternal health. Meanwhile, health authorities in Canada have expressed pregnant people should avoid cannabis altogether because of a potential risk of permanent damage and impairment to the offspring.
Alternatives and Safe Practices
Expectant mothers seeking to relieve common pregnancy symptoms like nausea or anxiety may be interested in safe alternatives. Ideally, beneficial lifestyle changes supported by research, dietary changes and interventions, prenatal supplements or vitamins, or other medications that their health care team or practitioners will assist with and that would not negatively impact fetal growth and development is the goal (that is the priority).
Conclusion
Cannabis use during pregnancy is a significant public health issue with consequences for fetal development, mothers’ health, and future outcomes for children. Though research is evolving, there is sufficient evidence to indicate that risks should arise with prenatal cannabis exposure, including low birth weight, preterm birth, neurocognitive deficits, and risks for mothers’ health during pregnancy.
