What you should know about marijuana use during pregnancy

More than half of Americans currently live in a state where marijuana and cannabis products are legal. Though some people use marijuana for medicinal or homeopathic reasons, it is still illegal in Indiana and strictly discouraged for pregnant women.

“Studies have shown that pregnant women who use marijuana more than twice a week are much more likely to have low birthweight babies than other mothers. They also may have increased risks of pre-term birth or even stillbirth,” said Dr. Kyle Mackey, an OBGYN at IU Health. “Those studies also found that these children may have lower intelligence scores and behavior problems later in life.”

Since marijuana is a Schedule I drug in Indiana, mothers who are smoking or using cannabis during pregnancy could face legal trouble and possible investigation by Child Protective Services if they continue using. However, there is help and support available.

Learn the answers to common questions about marijuana and pregnancy.

When should I stop smoking marijuana during pregnancy?

Much like cigarette or tobacco use, marijuana use should be stopped immediately when you discover you are pregnant. While heavy users may find it difficult to quit, there are ways to find support. Your doctor may have resources to recommend. Also, the Substance Abuse and Mental Health Services (SAMHSA) can offer support through its National Helpline.

“I start these conversations with my patients by reminding them that pregnancy is a very, very precious thing. You’re creating life,” Dr. Mackey said. "You are in charge, and this is something that potentially has negative effects on your pregnancy that you can control. I want to empower them with the knowledge that they can decide to quit.”

Does smoking affect breast milk?

Yes. Tetrahydrocannabinol, or THC, is the main chemical in marijuana that creates a “high” in users. THC affects the “endocannabinoid receptors” in our brain, which control some of our body functions like memory, sleep and emotions. THC can very easily cross the placenta and move from mother to baby. It’s also easily transferred into breastmilk. This is especially dangerous during the first trimester, when baby’s brain begins development.

“It’s very easy for substances that are fat soluble to pass into breast milk, and THC is very fat soluble,” Dr. Mackey said. “Babies would be getting THC from their mother’s use through breastmilk, so we discourage mothers from smoking during or after pregnancy.”

Are edibles safer than smoking marijuana?

It is not safer to consume marijuana in edibles than to smoke it, and babies would still feel the effects either way. In fact, it’s easier to overdose on THC through edibles. When you eat cannabis instead of smoking it, your body is slower to process the drug. People often consume more edibles to achieve a high and then feel overwhelmed by the drug when the effects finally begin.

Is it okay to continue using medical marijuana during pregnancy?

No. As with other prescribed drugs that may affect the baby, it is recommended to stop marijuana use once you are pregnant. Talk with your doctor about ways to safely address ongoing symptoms or conditions during pregnancy.

If I’m planning to become pregnant, should I stop using marijuana now?

Yes. You should stop taking all forms of marijuana if you are planning to become pregnant. The fetus brain begins developing early, and the receptors involved with brain development can start growing as early as the first trimester. Some women do not even know they are pregnant at this point, so quitting marijuana use beforehand is important.

Is it okay to ask my doctor about quitting marijuana?

Yes. While doctors have a mandate to document or report drug use among parents, a mother who wants to quit using marijuana during pregnancy will be offered support and options for quitting. The American College of Obstetricians and Gynecologists believes women who have a substance use problem should receive medical care and counseling services to support their efforts to quit.

Fortunately, Dr. Mackey says most women understand the importance of quitting.

“Seven percent of women use marijuana during pregnancy, and only about a third of them will continue to use throughout pregnancy,” he said. “Most women are able to quit, and it’s encouraging from that perspective.”