Cannabis and CBD in Pregnancy and Breastfeeding

Urgent first and a note on judgment

If a pregnant or nursing person has used cannabis and has severe symptoms, call 911 in the US, or US Poison Help at 1-800-222-1222. [1] If a child may have eaten a cannabis edible, call Poison Help right away. [1] See poison help by country. Anyone who is pregnant or nursing and has used cannabis should be able to talk with a health care provider without judgment; this page is education, not medical advice, and does not tell anyone to change medicines.

How to read this page

Evidence labels: evidence of harm (association), mixed, insufficient evidence, preclinical (animals only). "Association" means seen together, not proven to cause. The studies cited here adjusted for other factors, such as tobacco use, because people who use cannabis may also use tobacco. [2]

What the agencies say

• FDA (US). The FDA strongly advises against using CBD, THC and marijuana in any form during pregnancy or while breastfeeding. [3] (The page read is marked current as of March 2020.)
• Health Canada. There is not enough research to identify a "safe amount" of cannabis during pregnancy or breastfeeding. It also says edibles and vaping are not safer alternatives to smoking, and that cannabis is not recommended to treat morning sickness. [4]
• ACOG, as reported by NIDA. NIDA says the American College of Obstetricians and Gynecologists recommends counseling women against using cannabis while trying to get pregnant, during pregnancy and while breastfeeding. [1] The ACOG page itself could not be read this session (it is marked withdrawn).

Pregnancy: what research found

Birth outcomes. A 2025 systematic review and meta-analysis in JAMA Pediatrics pooled 51 studies (about 21 million participants) and looked at results adjusted for confounders such as tobacco use. It found moderate-certainty evidence that cannabis use in pregnancy was associated with higher odds of low birth weight (odds ratio 1.75), preterm birth (1.52) and being small for gestational age (1.57), and low-certainty evidence for higher perinatal mortality (1.29). [2] NIDA says research has linked cannabis in pregnancy with lower birth weight, preterm birth, hospitalization and death within one year of birth. [1] Label: evidence of harm (association).

Brain and behavior in children. A 2024 meta-analysis of 17 studies (534,445 participants) found after adjustment a slightly higher odds of ADHD in offspring (odds ratio 1.13, range 1.01 to 1.26) and of the child later using cannabis (1.20), but no clear association with autism, psychotic symptoms, anxiety or depression. The authors still advised caution and said more research is needed. [5] Label: mixed; small signals for ADHD, not for the other outcomes. The FDA reports that the US Surgeon General advised that marijuana use in pregnancy may affect fetal brain development because THC can enter the fetal brain from the mother's bloodstream. [3]

CBD in pregnancy

The FDA says there is no comprehensive research on the effects of CBD on the developing fetus, pregnant mother or breastfed baby, and that high doses of CBD in pregnant test animals caused problems in the reproductive system of developing male fetuses. [3] The label of the approved CBD medicine says there are no adequate data on its use in pregnant women, and that giving CBD to pregnant animals produced developmental toxicity. [6] Label: preclinical for harm; insufficient evidence in people. The FDA also warns that CBD products may be contaminated, including with THC. [3] See CBD quality and certificates of analysis.

Breastfeeding

• Transfer into milk. Health Canada says THC and CBD pass into breast milk and cannabis can remain there for days to weeks. [4] The FDA says milk can contain THC for up to six days after use. [3] The NIH LactMed database reports detection times from 6 days to more than 6 weeks across studies. [7]
• How much. In a pilot study of eight mothers, who each smoked a measured 0.1 g of cannabis (a study amount), THC was detected in milk at low concentrations. Infants were estimated to receive a mean of 2.5% of the maternal dose. [8] In a 2024 study of 20 breastfeeding people who used cannabis at least weekly, THC in milk peaked about 120 minutes after a single use, and repeated use led to build-up in most participants. [9]
• Effects on babies. Health Canada says THC can make a baby drowsy or have trouble latching and sucking. [4] LactMed says occasional use showed no discernable effects in older studies, but those studies could not rule out long-term harm and were done when cannabis was less potent. It also says daily or near-daily use might slow a breastfed infant's motor development in a one-year study, and that professional guidelines generally advise nursing mothers to avoid cannabis. [7] Label: insufficient evidence; agencies advise avoiding.
• Pumping and discarding. Health Canada says expressing and discarding milk does not reduce cannabis in the milk. [4]
• CBD. The approved CBD medicine's label says there are no data on whether CBD or its breakdown products are in human milk. [6] The FDA expects some CBD to be transferred to babies through breast milk. [3] The sources therefore differ on how much is known, which shows how limited the research is.
• Smoke. LactMed says cannabis should not be smoked near infants because they may inhale the smoke. [7]

If someone already used cannabis in pregnancy

Do not stop prescribed medicines without advice. The FDA's advice is to talk with a doctor, nurse or pharmacist before taking any medicines, vitamins or herbs while pregnant or breastfeeding. [3] Help lines for stopping are on dependence and withdrawal. See also pregnancy and breastfeeding safety for natural remedies and cannabis and adolescents.