Can Marijuana Use Before or During Pregnancy Cause Autism in Babies? 

In recent years, the prevalence of neurodivergence, such as Autism Spectrum Disorder (ASD) and ADHD, has grown, and so too has the research into what might cause such developmental conditions. 

In many cases, the cause of ASD is genetic, but for others, the cause is unclear, and researchers must consider a wide range of potential risk factors related to developmental differences in growing fetal brains. A number of environmental factors have come under scrutiny, such as the heavy metals found in a number of baby food brands. One of these factors is the (growing) use of marijuana among mothers-to-be. 

Ultimately, research findings are yet to conclusively prove a direct cause-and-effect relationship between the use of marijuana during pregnancy, and the development of autism. Still, the evidence so far does point towards a correlation that is alarming and should be carefully considered by expectant mothers.

Findings not reassuring on the effects of marijuana in utero

As reported by CNN in 2020, the largest study to date was conducted by researchers into the effects of using marijuana during pregnancy, and the findings concluded that it might increase the risk of the child developing autism.

Dr. Darine El-Chaar, Clinical investigator and maternal-fetal medicine specialist at Ottawa Hospital Research Institute, authored the study, concluding that women who use marijuana during pregnancy are 1.5 times more likely to have an autistic child. El-Chaar states in no uncertain terms that the use of cannabis during both pregnancy and breastfeeding is highly discouraged. 

These findings have also been described by associate professor of psychiatry and human behavior at Brown University, Stephen Sheinkopf, as ‘provocative,’ especially given the scale of the study. Out of 500,000 children from a birth registry, 7,125 had been diagnosed with ASD, and the prevalence of autism among those born to women who had used marijuana during the pregnancy was higher (2.22%) than those born with autism to mothers who had not used it (1.41%). 
Previous studies have also found a range of other health issues in children can be linked to marijuana use during pregnancy. These include low birth weight, hyperactivity, Attention Deficit Hyperactivity Disorder (ADHD), and other behavioral and cognitive issues. More troubling still, according to the U.S. Centers for Disease Control and Prevention, one study found that pregnant women who use marijuana are 2.3 times more likely to have a stillborn child.

Concerning rise in use of weed during pregnancy

Given the increased awareness surrounding the potential harm of other medications during pregnancy, such as the active ingredient acetaminophen found in Tylenol® and other pain and fever-fighting medications, more and more pregnant women are turning to weed.

As marijuana becomes more socially acceptable and its legalization more commonplace, medical experts fear that expectant mothers are increasingly turning to it to treat restlessness, poor sleep, morning sickness, anxiety, and more. According to the National Institute on Drug Abuse, the use of cannabis among pregnant women more than doubled from 2002 to 2017.

Marijuana potentially harmful when a child’s brain is developing.

The study also found that the most prevalent use of marijuana was in the first trimester (first three months) of pregnancy, and that this use is predominantly recreational. Given that the first trimester is arguably the most vulnerable time for the developing fetal brain with respect to being damaged, this statistic is concerning, especially with the link to autism thrown into the mix. 

What is Autism Spectrum Disorder (ASD)?

ASD is a developmental disorder that can cause a range of social, behavioral, and communication challenges. 

Given the wide range of symptoms that can present with ASD, each individual with ASD can exhibit quite differently in terms of both the symptoms themselves, and their severity; some people with autism can live completely independently, while others have high needs, and require daily care and support to assist them in living normal lives. 

Symptoms of ASD can include:

• Speech challenges, such as delayed speech development or slurring
• Monotone or robotic speech style
• Difficulty communicating with others
• Lacking clear facial expressions
• Difficulty reading others’ facial expressions, tone of voice, and other non-verbal cues
• Discomfort in maintaining eye contact
• Carrying out routines or rituals
• Trouble regulating their emotions
• Sensory issues, such as not liking being touched or trouble tolerating particular sounds
• Echolalia – involuntary repetition of others’ speech or sounds
• Hyperfixation/intense focus on particular subjects or activities
• Stimming – repetitive actions, such as rocking or hand-flapping that help to calm 

Many of these traits/behaviors may also be symptoms of unrelated conditions and entirely unrelated to ASD. Still, they are key indicators, so if your loved one is exhibiting some of these symptoms, consult your healthcare professional with expertise in developmental disorders.

What is the treatment for ASD?

There is no cure for autism, and current treatments are designed to seek a reduction in the symptoms that interfere with quality of life and daily functioning. Each person with ASD has both unique challenges and strengths, and will require a tailored treatment plan for best results. 

Treatments include Sensory Integration Therapy, Speech Therapy, Physical Therapy, and a wide range of complementary and alternative treatments, such as supplements, dietary changes, relaxation therapies, and more. Music therapy has also been found to be particularly effective, as those with ASD often find it easier to express themselves through music, as well as having it help to calm their minds and regulate their emotions (with the right music). 

Early intervention is the key to helping people with ASD, as the earlier treatments begin, the sooner the individual can be supported in social, behavioral, and communication improvements, among others. 

Play it safe

Any woman who is pregnant or planning to conceive should discontinue the use of marijuana as an informed precaution against a range of developmental issues, including autism. The research may not be bulletproof at this stage in terms of clarifying a positive cause-and-effect relationship between marijuana use and autism, but the links already established are enough to prompt researchers to urge caution. 

If you are pregnant, breastfeeding, or trying to fall pregnant and rely on cannabis, either recreationally or as a medical substitute, consult with your doctor and consider safer alternatives.

^{[1]  A Systematic Review of the Link Between Autism Spectrum Disorder and Acetaminophen: A Mystery to Resolve, interpreting data from Parker SE, Collett BR, Werler MM: Maternal acetaminophen use during pregnancy and childhood behavioural problems: Discrepancies between mother- and teacher-reported outcomes. Paediatr Perinat Epidemiol. 2020, 34:299-308. 10.1111/ppe.12601).}

^{[2] Paracetamol use during pregnancy—a call for precautionary action, Bauer, A.Z., Swan, S.H., Kriebel, D., Liew, Z., Taylor, H.S., Bornehag, C.G., Andrade, A.M., Olsen, J., Jensen, R.H., Mitchell, R.T. and Skakkebaek, N.E., 2021. Nature Reviews Endocrinology, 17(12), pp.757-766.}

^{[3]  A Systematic Review of the Link Between Autism Spectrum Disorder and Acetaminophen: A Mystery to Resolve, interpreting data from Parker SE, Collett BR, Werler MM: Maternal acetaminophen use during pregnancy and childhood behavioural problems: Discrepancies between mother- and teacher-reported outcomes. Paediatr Perinat Epidemiol. 2020, 34:299-308. 10.1111/ppe.12601).}

^{[4] Paracetamol use during pregnancy—a call for precautionary action, Bauer, A.Z., Swan, S.H., Kriebel, D., Liew, Z., Taylor, H.S., Bornehag, C.G., Andrade, A.M., Olsen, J., Jensen, R.H., Mitchell, R.T. and Skakkebaek, N.E., 2021. Nature Reviews Endocrinology, 17(12), pp.757-766.}