What are the effects of cannabis on pregnancy?

Cannabis (marijuana) use during pregnancy can be dangerous to the mother and the baby despite its growing popularity for managing pregnancy symptoms. Research from 2023 shows that THC and CBD cross the placenta and affect fetal development.

At our drug rehab center, we help women struggling with cannabis dependence build healthier pregnancies through evidence-based treatment tailored to their needs.

Why do some pregnant women use cannabis?

Many people view cannabis as harmless or even beneficial. Cannabis products are often marketed as “natural” remedies for different conditions, which leads many to believe they’re safer than pharmaceutical alternatives. While cannabis may offer therapeutic benefits for certain people, studies examining the effects of cannabis exposure show that pregnant women experience increased rates of gestational hypertension (elevated blood pressure in pregnancy), adverse pregnancy outcomes, and other negative effects.

Despite medical recommendations against prenatal use, cannabis remains the most commonly used illicit substance during pregnancy. According to Skelton, et. al. (2020), 5.5% of women (68 out of 1147) reported using cannabis during pregnancy. Research suggests that rates of prenatal cannabis use disorder have more than doubled from 2.8 to 6.9 per 1000 deliveries between 2001 and 2012.

Pregnant women report using cannabis for:

Relief from morning sickness and nausea.
Relief from pregnancy-related anxiety and stress.
Better sleep quality amid physical discomfort.
Reduction of pregnancy aches and pains.
Increased appetite and weight gain in early pregnancy.
Trust in cannabis as a natural alternative to prescription medications.
Self-medication for mood disorders and depression.
Continued use due to pre-pregnancy habits or dependence.

Many of these reasons may seem compelling, but cannabis use during pregnancy poses serious health hazards that outweigh potential short-term benefits.

How cannabis affects pregnant women and fetuses

The cannabis plant contains over 100 chemical compounds. Tetrahydrocannabinol, or THC, is the primary psychoactive component that crosses the placental barrier most efficiently and interferes with fetal brain development. Cannabidiol (CBD) and other minor cannabinoids are non-psychoactive and often promoted as safer alternatives to THC, all cannabis compounds can disrupt the endocannabinoid system in developing fetuses.

The endocannabinoid system regulates fetal development, brain formation, and neural wiring through chemical signaling. This complex cell-signaling network consists of endocannabinoid receptors, enzymes, and naturally occurring cannabinoids that regulate physiological processes (including neurodevelopment), cellular differentiation, and neural migration. During pregnancy, this system requires balance to orchestrate brain development and organ formation.

When external cannabinoids from marijuana enter the maternal bloodstream, they bind to the same receptors as natural endocannabinoids but with greater intensity and duration. This disruption can alter gene expression, interfere with cellular communication, and modify how neural circuits form, which can change the architectural blueprint of the developing brain in ways that manifest as behavioral and cognitive challenges throughout childhood and beyond.

Effects of cannabis on fetal development

Cannabis exposure during pregnancy results in reduced birth weight averaging approximately 100 g lower than babies not exposed to cannabis (Badowski and Smith, 2020). This effect is dose-dependent, and continued use throughout pregnancy causes greater reductions in birth weight than early pregnancy use only.
Prenatal cannabis use leads to shorter gestational age and increased risk of preterm birth, which creates additional health challenges for newborns. According to a 2022 study, premature babies often face feeding difficulties, trouble regulating body temperature, and higher susceptibility to infections.
Newborns exposed to cannabis in utero commonly exhibit a “withdrawal-like” syndrome. They show neurological symptoms of startles and tremors and reduced habituation to light.
Medical imaging shows that cannabis exposure causes altered brain structure and disrupted normal brain development, mainly in areas responsible for higher cognitive functions.
Prenatal marijuana exposure impairs neural circuit formation, which affects how brain cells communicate with each other. These disruptions can permanently alter how the brain processes sensory information and regulates emotions.
Researchers have found that THC can accumulate in fetal tissues at concentrations higher than those detected in maternal blood. As a result, the developing fetus experiences prolonged exposure to cannabis compounds, even after the mother has stopped using.

Effects of cannabis on maternal health

Cannabis use during pregnancy increases the risk of anemia in expecting mothers. Gerede, et. al. explain that this condition reduces oxygen transport to maternal and fetal tissues and compromises their health and fetal development. The research team also found that cannabis consumption in expecting mothers “has been associated with several adverse obstetric outcomes, with the most consistent associations including an elevated risk for hypertensive disorders, placental abruption, and fetal growth restriction.”
Pregnant women who use cannabis experience compromised immune function, making them more susceptible to infections and illnesses. These infections can further complicate pregnancy and potentially affect fetal development.
High levels of THC impair judgment and decision-making abilities. This may lead to poor prenatal care decisions or increased risk-taking behaviors.
A 2024 cohort study documented higher rates of pregnancy complications among cannabis users, including placental abruption and preeclampsia. Cannabis users face longer and more complicated labor and delivery experiences. This extended labor process increases maternal exhaustion and the need for medical interventions.
Cannabis use correlates with a greater likelihood of postpartum depression. Eitel, et. al. show that postpartum cannabis use “contributes to poor infant and child health outcomes” and is “thought to be associated with […] mental health problems (e.g., depression).” Untreated postpartum depression can interfere with mother-infant bonding and infant development.
Pregnant cannabis users often develop tolerance and dependence. When mothers with cannabis dependence during pregnancy stop using, they may experience withdrawal symptoms at a time when they’re already navigating the significant adjustments of new parenthood.

If you’re pregnant and struggling with cannabis use, Ardu provides comprehensive treatment programs to help you achieve a healthier pregnancy. At our medical detox center, we help you safely taper off cannabis as we address the underlying reasons for your dependency through evidence-based alternatives.

How bad is secondhand smoke during pregnancy?

Smoking cannabis remains the most common method of consumption, and the most hazardous one. The burning process exposes users to harmful combustion byproducts not present in the plant itself, including tar, carbon monoxide, and carcinogens similar to those found in tobacco smoking. These toxins damage lung tissue, impair respiratory function, and cause a range of problems from increased phlegm production to chronic bronchitis symptoms and airway inflammation.

These risks extend beyond the expecting mother to affect fetal development because harmful compounds in cannabis smoke cross the placental barrier much easier than other consumption methods. Even secondhand cannabis smoke can be harmful, with risks including intensive care unit admission for newborns with respiratory complications.

Whether through smoking, vaping, edibles, or oils, the active compounds in cannabis can adversely affect prenatal development and maternal health outcomes. If you’re pregnant, avoid both using cannabis and being around others who are smoking or vaping it.

How long does cannabis stay in your system during pregnancy?

Cannabis compounds remain in the body much longer during pregnancy than in non-pregnant women. The fat-soluble nature of THC means it’s stored in body fat and can circulate between the maternal bloodstream, the placenta, and fetal tissues for extended periods.

In pregnant women, detection times depend on the consumption method and frequency.

In blood samples, THC remains detectable for 2–7 days after occasional use but can persist for more than 30 days if used regularly.
Urine tests can identify cannabis use for about 3–30 days, with longer detection windows for frequent users.
THC’s presence in amniotic fluid can be detected for over a month after the mother’s last use.
Because THC accumulates in fetal tissues in amounts that exceed levels found in the mother’s bloodstream, babies experience prolonged exposure to cannabis compounds even after the mother stops using.

Researchers from the Oregon Health & Science University state that cannabis compounds cross the placental barrier throughout all trimesters of pregnancy and that exposure in each trimester is linked to different developmental concerns.

If you’re pregnant and concerned about cannabis use, reach out to our Provo, Utah rehab center for specialized support to help you navigate this challenging time. Our confidential pregnancy substance assessment provides personalized guidance without judgment. We have medical experts on our team who will monitor you 24/7 and cater to the unique needs of expectant mothers.

Don’t wait until your next prenatal appointment. Contact Ardu today to discuss options for creating the healthiest possible environment for you and your baby.

Is it okay to use cannabis during postpartum?

Many women who abstained from cannabis during pregnancy resume use after giving birth. Some believe that once delivery occurs, the risks to the baby are eliminated. This misconception overlooks continued risks in the postpartum period, whether a mother is breastfeeding or not.

Here are the ways cannabis use affects postpartum women and their babies:

Cannabis compounds transfer to infants through breast milk and can be detected for up to six days after maternal use.
THC consumption impairs maternal attention, coordination, and reaction time, which can compromise a new mother’s ability to safely care for her newborn.
As we explained before, cannabis use is associated with an increased risk of postpartum depression and anxiety. This can interfere with maternal-infant bonding and have adverse effects on child behavior. Mothers who use cannabis may have reduced sensitivity to their baby’s needs.
Regular cannabis use disrupts sleep and quality, further compounding the sleep deprivation common in the postpartum period.
Women with a history of pregnancy-related hypertensive disorders may experience worsening cardiovascular effects from cannabis use.
Mothers who use cannabis postpartum tend to stop breastfeeding earlier than non-users, which prevents infants from receiving the full nutritional and immune-boosting benefits of human milk.
Cannabis smoke in the home environment increases an infant’s risk of respiratory problems similar to tobacco smoke exposure.

When to seek help for cannabis use during pregnancy

If you’re using cannabis during pregnancy or struggling to quit despite knowing the risks, it’s time to seek professional help. The sooner you address cannabis use during pregnancy, the better the outcomes for you and your baby.

At Ardu, we understand the unique challenges pregnant women face when dealing with cannabis dependence, so we offer specialized treatment programs that protect maternal health and fetal development while addressing the underlying reasons for cannabis use.

Our cannabis detox services

Our drug detoxification program for pregnant women includes:

Medically supervised cannabis withdrawal management that prioritizes maternal and fetal safety.
24/7 monitoring by healthcare providers with expertise in addiction medicine and women’s health.
Nutritional support to address appetite changes and facilitate proper fetal development.
Management of withdrawal symptoms with pregnancy-safe interventions.
Coordination with your obstetrician for a more comprehensive prenatal care.

Our cannabis rehabilitation services

Following detoxification, our comprehensive rehabilitation program offers:

Evidence-based therapies including CBT and dialectical behavioral therapy to address underlying reasons for cannabis use.
Dual diagnosis treatment for co-occurring mental health issues such as anxiety, depression, or PTSD.
Mindfulness-based therapy that builds sustainable alternatives to cannabis for stress management.
Family therapy to strengthen your support system during recovery.
Holistic addiction treatment approaches including yoga, acupuncture, and meditation.
Relapse prevention strategies tailored to the postpartum period.
Parenting skills development to build confidence in drug-free childcare.

Our team of healthcare professionals brings expertise in addiction medicine and reproductive health. We create individualized treatment plans that account for the physiological and emotional aspects of cannabis dependence during this critical time.

Don’t wait until after delivery to address cannabis use. Contact Ardu online or give us a call and learn how our compassionate, science-based approach can support your journey toward a healthier pregnancy and motherhood.

Written by Brandon Okey. Mina Draskovic, B.Psy., reviewed this content for accuracy.

Cannabis and pregnancy FAQ

Is cannabis bad for fertility?

Cannabis can negatively impact fertility for men and women. In women, cannabis disrupts the endocannabinoid system which regulates reproductive function, potentially causing menstrual cycle irregularities and ovulation problems. Regular cannabis use may delay conception and increase risk of pregnancy complications. For men, marijuana use is associated with reduced sperm count, decreased sperm motility, and abnormal sperm morphology.

These effects appear dose-dependent. Heavy users experience more serious fertility challenges. If you’re struggling to conceive and use cannabis regularly, discuss this with your healthcare provider as part of a comprehensive fertility assessment.

What if I smoked weed before I knew I was pregnant?

Many women use cannabis before discovering they’re pregnant, especially during the first trimester. Fortunately, a single exposure doesn’t guarantee harm to your baby. You should stop using cannabis upon learning you’re pregnant. Early prenatal exposure carries greater risk for fetal development than maternal marijuana use before conception.

Is it safe to take cannabis oil while pregnant?

Cannabis oil is not safe during pregnancy, regardless of whether it’s marketed for medicinal purposes or recreational use. All cannabis products, including oils, tinctures, and edibles, contain compounds that cross the placental barrier and may disrupt fetal development. Cannabis oil often contains concentrated levels of THC and other cannabinoids that can affect the developing endocannabinoid system in your baby.

Studies show intrauterine exposure to medical marijuana from any delivery method poses health risks to fetal growth and brain development. If you’re using cannabis oil for medical reasons, like nausea or anxiety, consult your healthcare provider about pregnancy-safe alternatives with established safety profiles.

What is fetal cannabis syndrome?

While “fetal cannabis syndrome” isn’t an officially recognized medical diagnosis (like fetal alcohol syndrome), researchers use this term to describe the collection of effects observed in babies exposed to cannabis in utero. These effects can include low birth weight, reduced head circumference, impaired fetal growth, and characteristic neurobehavioral issues such as increased tremors, startles, and high-pitched crying in newborns.

Long-term effects of prenatal cannabis exposure include problems with executive functioning, attention deficits, cognitive development challenges, and higher rates of delinquent behavior in childhood. Unlike some other prenatal exposures, the effects of cannabis aren’t visible at birth but often become apparent in mental development and academic achievement as the child grows.

How long does CBD stay in your system?

CBD typically remains in your system for 2–5 days, but detection times depend on several factors. For frequent or heavy users, CBD may be detectable for up to more than 30 days, especially in body fat where cannabinoids tend to accumulate. Higher doses remain detectable longer. Most standard illicit drug tests don’t screen for CBD but may detect THC if your CBD product contains it. During pregnancy, elimination times may be extended due to changes in metabolism. The effects of CBD wear off within hours, but the compound persists much longer.

Can I drink coffee while pregnant?

Most healthcare providers consider moderate coffee consumption safe during pregnancy. Some women find their taste for coffee naturally decreases during pregnancy, especially during the first trimester. Current guidelines suggest limiting caffeine to 200 mg daily (about one 12 oz cup of coffee). Excessive caffeine has been associated with increased risk of miscarriage and low birth weight, similar to some effects of marijuana but with clearer safety thresholds. Coffee doesn’t cross the placental barrier the way THC does, nor does it accumulate in fetal tissues. If you’re reducing cannabis use during pregnancy, be cautious about substituting caffeine as an alternative.

Resources

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