Key Takeaways

• New guidance urges all pregnant patients to avoid cannabis

• THC crosses the placenta and can contaminate breast milk

• Screening should be supportive and not rely on drug testing, experts say

MONDAY, Sept. 22, 2025 (HealthDay News) — Pregnant people should stay away from cannabis, and doctors should ask all patients about its use before, during and after pregnancy, according to new guidance from the American College of Obstetricians and Gynecologists (ACOG).

The recommendations come as cannabis use during pregnancy has climbed in the U.S., following wider legalization and social acceptance. 

A 2019 analysis of more than 450,000 women ages 12 to 44 found cannabis use more than doubled between 2002 and 2017, according to the National Institute on Drug Abuse (NIDA).

“When things become more normalized in society, it’s a very natural tendency for us to think that we don’t have to think about the potential risks,” Dr. Amy Valent, an OB/GYN at Oregon Health & Science University in Portland who helped develop the new guidance, told CNN.

Researchers now know that THC, the psychoactive compound in cannabis, can cross the placenta and transfer into breast milk. Cannabinoid receptors have been found in fetuses as early as five weeks, raising concerns about exposure.

The guidance links cannabis use in pregnancy with low birth weight, neonatal intensive care admissions, perinatal death and possible long-term neurodevelopmental effects such as attention deficits and learning problems.

Still, data on cannabis safety in pregnancy remain limited, Valent noted.

“People have been using cannabis for years, and it’s not associated, as far as we know, with … birth defects,” she told CNN. “But should that be the bar for pregnancy safety?”

ACOG strongly discourages drug testing pregnant people using hair, urine or other samples, saying these tests can fuel discrimination against minority patients. 

Instead, the group recommends universal screening through conversations and interview methods.

Doctors should approach the subject carefully and without judgment, experts say. “Would it be OK with you if I asked you some questions about cannabis and other drug use?” is one way to begin, suggested Dr. Cara Poland, an addiction medicine physician at Michigan State University who was not involved with the guidance.

Unlike with conditions such as gestational diabetes, substance use during pregnancy can trigger involvement of child protection agencies. Because these laws vary, ACOG urges providers to be aware of local policies.

Many patients use cannabis to cope with nausea, stress or anxiety during pregnancy, but ACOG emphasizes that better communication about symptoms may help reduce reliance on it. 

In some cases, cannabis may even worsen nausea. Alternatives such as exercise, dietary adjustments or approved medications may help, CNN said.

“The benefit of screening is that it starts conversations and then comes individualization to patient needs,” Valent said. “We really need to be able to talk more broadly with our patients about their symptoms and how we can best support them. I think there’s beauty to communication and conversation, and hopefully this guidance just helps support people to understand that we just want to provide a more comprehensive conversation.”

More information

The U.S. Centers for Disease Control and Prevention has more on cannabis and pregnancy.

SOURCE: CNN, Sept. 18, 2025

What This Means For You

If you’re pregnant or planning to be, experts recommend avoiding cannabis.