Cannabis use during pregnancy may be associated with a higher risk of miscarriage, but researchers have not proven that cannabis directly causes miscarriage. The evidence comes mainly from observational studies, which cannot rule out other factors such as tobacco use, alcohol, or underlying health conditions. Because of this uncertainty, major health organizations recommend avoiding cannabis while pregnant or trying to conceive.
cannabis use while pregnant third trimester
What the research says about cannabis and miscarriage
Several studies have found a link between cannabis use in early pregnancy and a higher risk of miscarriage. Some research suggests the risk may be greater with frequent or heavy use. However, other studies have found no significant increase after adjusting for factors like tobacco, alcohol, and maternal age. The mixed results mean that a direct cause-and-effect relationship has not been established.
Why the evidence is not definitive
Most human studies on cannabis and miscarriage are observational. They rely on people reporting their own cannabis use, which can be inaccurate. They also cannot fully separate cannabis from other behaviors and health conditions that affect pregnancy. For example, people who use cannabis may also use tobacco or have untreated health problems. These factors can independently raise miscarriage risk. Additionally, studies use different definitions of cannabis use, such as frequency, method, and timing. This makes it hard to compare results and draw firm conclusions.
Other known risks of cannabis in pregnancy
Even if the miscarriage link remains unclear, cannabis use during pregnancy is tied to other harms. These include:
- Low birth weight
- Preterm birth
- Increased risk of stillbirth
- Long-term developmental and behavioral issues in children
Because of these risks, the American College of Obstetricians and Gynecologists (ACOG) recommends that pregnant women be screened for cannabis use and advised to stop. The Centers for Disease Control and Prevention (CDC) also advises against cannabis use during pregnancy.
What to do if you are pregnant and use cannabis
If you are pregnant or trying to conceive and use cannabis, talk to your healthcare provider. They can discuss the potential risks and help you find safer alternatives for conditions like nausea or anxiety. Do not stop suddenly if you use cannabis heavily, as withdrawal can be uncomfortable. A doctor can provide support and monitoring. If you are not pregnant but could become pregnant, avoiding cannabis is the safest choice.
Bottom line
Can cannabis cause miscarriage? The honest answer is that we do not know for sure. A link is possible, especially with frequent use, but causation is not proven. Given the known risks to pregnancy and child development, health experts recommend avoiding cannabis entirely while pregnant or trying to conceive. When in doubt, consult your healthcare provider for personalized advice.