06/19/2026
THC Use During Pregnancy: What Every Expectant Parent Should Know
What Is THC?
THC (tetrahydrocannabinol) is the main chemical in ma*****na that causes a person to feel "high." THC is found in ma*****na products that are smoked, vaped, eaten (edibles), or used in other forms.
If you use ma*****na while pregnant, THC can pass through the placenta and reach your baby.
How Does THC Affect Your Baby?
Understanding the Endocannabinoid System
Your body has a natural system called the endocannabinoid system (ECS). This system helps control important functions such as mood, appetite, sleep, pain, and brain development. The ECS also plays an important role during pregnancy.
It helps with:
Implantation of the embryo
Growth of the placenta
Fetal growth and development
Development of the baby's brain and nervous system
As your baby grows, special receptors in the brain help guide learning, memory, movement, and behavior. THC can attach to these receptors and may interfere with normal development.
Because THC crosses the placenta, it can affect the developing baby during important stages of growth.
New Research on THC and Baby's Heart Development
Researchers are learning more about how THC may affect a baby's developing heart.
The heart begins forming very early in pregnancy. Studies show that THC can cross the placenta and reach the baby during this important stage of development. Scientists believe THC may interfere with normal heart formation by affecting signals that help the heart grow and develop.
Some recent studies have found a possible link between ma*****na use during pregnancy and certain birth defects of the heart, including:
Atrial Septal Defect (ASD) – a hole between the upper chambers of the heart
Ventricular Septal Defect (VSD) – a hole between the lower chambers of the heart
Large population studies in the United States and Europe have reported higher rates of these heart defects in areas where prenatal cannabis exposure was more common. Other studies suggest that babies exposed to ma*****na before birth may have a higher risk of heart abnormalities compared with babies who were not exposed to ma*****na.
While researchers continue to study this possible connection, health experts are concerned enough that they recommend avoiding all THC and cannabis products during pregnancy.
Because THC may affect the baby's brain, growth, and heart development, organizations such as the Centers for Disease Control and Prevention (CDC), the American College of Obstetricians and Gynecologists (ACOG), and the March of Dimes recommend not using ma*****na during pregnancy or while breastfeeding.
More research is needed to fully understand how THC affects fetal heart development, but current findings support avoiding ma*****na use during pregnancy whenever possible.
What Does Research Show?
Studies show that babies exposed to ma*****na during pregnancy are more likely to have a lower birth weight than babies who were not exposed.
A baby with a low birth weight may have a higher risk of health problems during infancy.
Research also suggests that THC exposure during pregnancy may affect fetal growth and increase the risk of some pregnancy and newborn complications.
Pregnancy Complications
Researchers are still learning about all the effects of ma*****na use during pregnancy. Some studies suggest that ma*****na use may increase the risk of pregnancy complications for the mother.
However, it can be difficult to know exactly how much ma*****na contributes because other factors, such as to***co use, alcohol use, and overall health, may also affect pregnancy outcomes.
Effects on Newborns
Babies exposed to ma*****na before birth may be more likely to need care in a Neonatal Intensive Care Unit (NICU) after delivery.
A NICU stay does not always mean a baby will have long-term health problems. It simply means the baby may need extra monitoring or medical care after birth.
What About Long-Term Effects?
Many parents worry about how THC exposure might affect their child's future learning and development.
Researchers are still studying whether ma*****na use during pregnancy causes:
Sudden Infant Death Syndrome (SIDS)
Learning or memory problems
Lower school performance
Future substance use problems
Currently, there is not enough evidence to know for sure. More research is needed.
This does not mean ma*****na is safe during pregnancy. It means scientists are still learning about the long-term effects.
Why Is Avoiding THC Important?
Ma*****na products today are often much stronger than they were years ago. Different products contain different amounts of THC, and there is currently no known safe amount of THC during pregnancy.
Because THC can reach the baby and may affect growth, brain development, and heart development, healthcare experts recommend avoiding ma*****na during pregnancy and while breastfeeding.
What If You Use Ma*****na for Nausea, Anxiety, or Sleep?
Some people use ma*****na to help with:
Morning sickness
Anxiety
Pain
Trouble sleeping
If you are pregnant or planning to become pregnant, talk with your physician before using ma*****na or THC products.
There may be safer treatments available for your symptoms.
Do not stop any prescribed medication without talking to your healthcare provider first.
Key Takeaways
Current research shows that THC use during pregnancy may:
✓ Increase the risk of low birth weight
✓ Increase the chance of pregnancy complications
✓ Increase the likelihood that a newborn may need NICU care
✓ Affect normal fetal growth and development
✓ May increase the risk of certain heart defects, including atrial septal defects (ASD) and ventricular septal defects (VSD)
✓ May affect the development of the baby's brain and heart
Because no safe level of THC use during pregnancy has been established, avoiding ma*****na is the safest choice for you and your baby.
When to Talk to Your Physician
TALK TO YOUR PHYSICIAN IF:
You are pregnant and currently use ma*****na
You are planning a pregnancy and use THC products
You are using ma*****na for nausea, anxiety, pain, or sleep problems
You have questions about how THC may affect your baby
Your healthcare team can help you find safe options to support a healthy pregnancy.
References
National Academies of Sciences, Engineering, and Medicine. The Health Effects of Cannabis and Cannabinoids: The Current State of Evidence and Recommendations for Research. Chapter 10: Prenatal, Perinatal, and Neonatal Exposure to Cannabis.
American College of Obstetricians and Gynecologists (ACOG). Committee Opinion No. 722: Ma*****na Use During Pregnancy and Lactation.
Centers for Disease Control and Prevention (CDC). Cannabis and Pregnancy.
March of Dimes. Ma*****na Use During Pregnancy.
Tadesse AW, Ayano G, Dachew BA, Tusa BS, Damtie Y, Betts K, Alati R. The association between prenatal cannabis use and congenital birth defects in offspring: A cumulative meta-analysis. Neurotoxicol Teratol. 2024 Mar-Apr;102:107340. doi: 10.1016/j.ntt.2024.107340. Epub 2024 Mar 7. PMID: 38460861.
