Marijuana During Pregnancy: Is It Safe? - BabyCenter

Thinking about using weed while you're pregnant? You're not alone – it's a common question, especially now that marijuana is legal in many states and easier to access than ever. But just because something's legal doesn't mean it's safe for pregnancy. 

Here's what the science says about marijuana, how it affects your baby, and why health experts strongly recommend pressing pause on the green while you're expecting.

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Key Takeaways

• Marijuana usage during pregnancy is linked to preterm birth, low birth weight, and developmental delays in young children.
• Experts recommend quitting marijuana altogether when you're pregnant because there's no known safe dosage. After your baby's born, it's not safe to use marijuana while you're breastfeeding, either.
• ACOG now recommends healthcare providers ask pregnant women about their marijuana usage and be prepared to discuss the risks posed by cannabis, as well as how to quit.

What happens if I smoke weed while pregnant?

First up, a quick biology lesson (bear with us if you already know this): The main psychoactive ingredient in marijuana – the ingredient that makes people "high" – is tetrahydrocannabinol, or THC. 

If you use marijuana when you're pregnant, THC crosses through the placenta into your baby's bloodstream. An estimated 10 to 30% of the THC in your system could reach your baby, and babies are much more vulnerable to the effects of chemicals and toxins than adults.

Essentially, there's no "safe" method to consume THC while pregnant. It'll pass from you to your baby if you're using marijuana in any way, including:

• Smoking: inhaling from a joint, bong, pipe, or other vessel
• Dabbing: using concentrated cannabis oil
• Vaping: inhaling cannabis vapor using a vaporizing pen or similar device
• Consuming marijuana edibles or cannabis-infused beverages. Edibles such as cookies, brownies, or candy aren't safer than smoking, dabbing, or vaping weed – the THC still crosses the placenta and you may not be aware of how much you're ingesting.

Even applying creams or lotions containing marijuana to your skin can potentially be a problem. Also, weed may be contaminated with other drugs or herbicides that could harm your baby – even if you buy marijuana legally.

Note: Vaping is especially dangerous because it has been linked to serious lung problems and deaths. The Food and Drug Administration (FDA) and the CDC warn that pregnant women shouldn't use any vaping products, including THC-containing products and e-cigarettes.

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Effects of smoking weed while pregnant

Smoking weed (or tobacco) while pregnant raises carbon monoxide levels in your blood. This can reduce the amount of oxygen that your developing baby receives, which can adversely affect your baby's growth.

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In a study of more than 5,600 women who used marijuana during their pregnancies, researchers found that compared to pregnant women who didn't use, pregnant women who used weed had:

• More than double the rate of preterm birth
• Increased rates of placental abruption

In the same study, the babies of the pregnant women who used marijuana were more likely to:

• Be small for gestational age
• Be transferred to neonatal intensive care (NICU)
• Have five-minute Apgar scores lower than 4 out of 10 (meaning the baby is more likely to need some extra medical attention in the hospital)

Research elsewhere has linked marijuana use in pregnancy to these effects on babies:

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• Increased irritability in newborns.
• Possible link to stillbirth: Researchers aren't sure yet if marijuana alone is responsible for the link or if other substances, such as cigarettes, are involved in the increased risk.
• Problems with higher-order thinking during childhood, including problem-solving, memory, planning, and attention span.
• More frequent instances of aggressive behavior by age 5.
• Lower academic scores once the child reaches school age.

Not all studies have identified ill effects from marijuana during pregnancy. But given the concerns that research has raised so far, the American Academy of Pediatrics and American College of Obstetricians and Gynecologists (ACOG) advise pregnant and nursing women to avoid marijuana use. Once your baby arrives, exposure to secondhand smoke from marijuana is also harmful.

ACOG also recommends that you avoid marijuana if you're trying to get pregnant, as you may become pregnant and not realize it right away. Even in the early weeks of the first trimester, marijuana could impact your baby's health. 

Also, THC gets stored in your fat and is released for a while after you stop using marijuana (estimates range from two days to several months), so it's a good idea to give up weed well before you conceive.

If you're feeling overwhelmed by all this info, you're not alone. The BabyCenter appOpens a new window breaks down what's happening in your pregnancy each week – including what's safe and what to steer clear of – so you're never left guessing.

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What effects can marijuana have on my health when I'm pregnant?

Using weed during pregnancy can have negative effects on your health, including:

• Risk of falling: Marijuana can make you dizzy. Falling can be especially dangerous when you're pregnant.
• Impaired judgment: You're more likely to injure yourself if you're under the influence.
• Risk of breathing problems: This is because marijuana lowers oxygen levels in your body.
• Lung damage: Marijuana smoke, much like cigarette smoke, irritates the lungs and may cause an increased risk of lung infection.

Are there benefits to using marijuana while pregnant?

While some mothers self-report that marijuana helped them manage nausea and morning sickness during their pregnancies, there's no scientific evidence that supports these claims. 

Furthermore, experts agree that the risks of using weed during pregnancy far outweigh any potential upsides.

There are plenty of ways to mitigate the discomfort from those symptoms that don't include marijuana use; there are natural remedies for morning sickness, and if those don't work, anti-nausea medications are an option.

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Anecdotally, some pregnant women report using weed to relieve other pregnancy symptoms such as achiness and loss of appetite. Again, the risks outweigh any potential benefits, and there are no studies that support this.

Medical marijuana generally contains higher CBD content and lower THC content. The use of CBD in pregnancy hasn't been studied well, so it's unknown if medical marijuana poses less risk to a baby than recreational marijuana. 

If you use medical marijuana, talk with your healthcare provider about other treatments that are safer to use during pregnancy.

Should I tell my doctor I'm using marijuana while pregnant?

Because cannabis has become legal in several states and is more accessible than ever, usage is at an all-time high – both in pregnant and non-pregnant people. (One study indicated that up to 16% of pregnant and lactating people are using marijuana, but take that with a grain of salt.)

Thus, ACOG is recommending that doctors initiate verbal screening: a conversation about marijuana with their pregnant and breastfeeding patients. The organization is advising that all providers make sure their patients know that there are no proven benefits to using marijuana while pregnant and suggest ways to quit. 

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ACOG is not recommending that healthcare providers start biologically testing patients for cannabis. So no, they won't be testing your pee for weed.

"ACOG's recommendation for cannabis screening of all pregnant women is not a new recommendation, and not different from what ob-gyns have been doing for decades," explains Layan Alrahmani, a board-certified ob-gyn and member of the BabyCenter Medical Advisory Board. "When we first see a patient, a part of the social history intake is to ask if the patient is using any substances."

Yet because of the stigma associated with marijuana and the very real health risks, women are unsure about talking with their doctors about it. Some mothers then go online for more information about how the drug may impact their pregnancy, and may encounter misinformation on forums.

The BabyCenter Community boards are full of moms talking about their thoughts on marijuana and pregnancy. User SillyGooseRaeRae sums it up nicely:

"​​While I have had multiple friends that have smoked weed while pregnant (and neither them or their babies suffered any issues because of it, nor did CPS get involved), I wouldn't trust my friends or any other random person on the internet when it comes to my baby's health. Your safest bet is truly to talk to your provider about it, or even find a second educated opinion if you want more information."

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Will I get in trouble for using marijuana while pregnant? 

This is tricky, because providers in some states may be required to report you to child welfare authorities if they suspect you of prenatal drug use. 

Part of ACOG's new guidelines is the recommendation that healthcare providers be aware of their state's laws and "should actively work to address inequities inherent in many existing systems." 

Still, you may be putting yourself at risk for legal action if you live in a state that considers prenatal substance use to be child abuse or neglect. This is the case in 24 states: Alabama, Arizona, Arkansas, Colorado, Florida, Georgia, Illinois, Indiana, Iowa, Kansas, Louisiana, Massachusetts, Michigan, Minnesota, North Dakota, Ohio, Oklahoma, South Carolina, South Dakota, Tennessee, Texas, Utah, Virginia, and Wisconsin (as well as Washington, D.C.). To find out about the laws where you live, check this summary of state lawsOpens a new window.

Women risk losing custody of their children, and several states require women who use drugs during pregnancy to undergo mandatory drug treatment. Three states threaten criminal charges.

Even in states where marijuana is legal for medical and/or adult use, smoking weed while pregnant can get you in trouble. In Colorado, for example, where marijuana is sold legally, hospitals may notify child protective services if your baby tests positive for THC at birth.

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The remaining states do not classify it as child abuse or simply don't address prenatal marijuana use within their laws at all.

For confidential and anonymous help, the Substance Abuse and Mental Health Services Administration (SAMHSA) offers:

• Online treatment services locator
• 24-hour assistance line: 800-662-HELP (4357)

Why don't we know more about using marijuana during pregnancy?

It's difficult to study the specific effects of using marijuana during pregnancy for several reasons, including:

• Women in studies may also be using tobacco, alcohol, or other drugs, so it's hard to isolate the effects of weed.
• Pregnant women may not want to admit they're using marijuana or how much they're using.
• Ethical concerns and the federal classification of marijuana as a Schedule 1 drug prevent researchers from conducting clinical trials involving weed and pregnant women.

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A final word

Let's say you're caught between a rock and a hard place: You've smoked weed during conception or pregnancy and you're worried, but you live in a state with mandatory reporting. 

You can ask your healthcare professional for information in a general way. Maybe you have a friend who smoked while pregnant or you've heard there's new research and want to know the scoop. Having a conversation about hypotheticals is not equivalent to admitting you've partaken and medical professionals need to have your informed consent to administer a drug test.