CBD and pregnancy and breastfeeding: what science says and when to exercise caution
Is CBD safe during pregnancy and breastfeeding? What does science say? WHO and ACOG do not recommend CBD for pregnant women. Read why and what studies say.
CBD is gaining popularity as a natural remedy for nausea, pain, anxiety, and sleep issues — all of which are common during pregnancy. It is no surprise that more and more women are considering the use of CBD oil during pregnancy or breastfeeding. However, the response from science and medicine is clear and requires attention. This article presents all available scientific evidence — without reassurance and without alarmism, but with full transparency regarding what is unknown.
KEY INFORMATION
• ACOG (American College of Obstetricians and Gynecologists, 2017) advises against the use of cannabis in any form during pregnancy and while breastfeeding.
• CBD crosses the placental barrier — Bertrand et al. (PMC, 2018) demonstrated the transfer of cannabinoids across the placenta in a human model.
• The endocannabinoid system plays a crucial role in the neurological development of the fetus — disruptions in its signaling can be potentially dangerous.
• There is a lack of randomized clinical trials assessing the safety of CBD in pregnancy in humans — and this gap is the main reason for caution.
• Recommendation: do not use CBD during pregnancy or while breastfeeding. Consult alternatives with your doctor.
Why does CBD in pregnancy raise concerns?
CBD in pregnancy is a subject of particular caution for several reasons that are worth understanding, rather than simply accepting as an authoritative recommendation. The key lies in the biology of the endocannabinoid system (ECS) and its role in fetal development.
The endocannabinoid system — CB1 and CB2 receptors, as well as the endogenous cannabinoids anandamide and 2-AG — is active in the fetus from the early weeks of pregnancy. The ECS plays a crucial role in: neuronal migration in the developing brain, synaptogenesis (the formation of neural connections), regulation of the cell cycle, and apoptosis (programmed cell death). This means that any external substance affecting the ECS — including CBD — can potentially disrupt these processes in the developing fetus.
CBD is not an agonist of CB1 and CB2 like THC — the mechanism of action of CBD is different and more complex (FAAH, TRPV1, 5-HT1A, GPR55, etc.). However, CBD affects the concentration of endogenous cannabinoids by inhibiting FAAH — the enzyme that breaks down anandamide. Higher levels of anandamide may influence CB1 signaling, and this signaling is important for the proper development of the nervous system. This provides a mechanistic justification for caution — not proof of harm, but a real risk that requires further research.
Does CBD cross the placenta?
Yes — and this is a key fact for any woman considering CBD during pregnancy. The placental barrier is not an impermeable wall — it is selectively permeable, and many substances, including medications, supplements, and exogenous substances, can cross it to reach the fetus.
Bertrand et al. (PMC, 2018) conducted one of the first studies on a human placental model, demonstrating that cannabinoids — including CBD — cross the placental barrier. The study used a perfused ex vivo placental model with a term delivery, allowing for the assessment of substance transfer through placental tissue without ethical issues in vivo. The results confirmed the detection of cannabinoids on the fetal side — meaning that CBD taken by the mother can reach fetal circulation.
CBD concentrations detected on the fetal side in laboratory experiments are lower than on the maternal side — the placenta is a protective mechanism, but not an absolute barrier. The key question is: what concentration of CBD in the fetus is biologically active, and can supplemental doses in the mother reach these concentrations? We do not know — and this uncertainty is crucial. In medicine, the principle of "primum non nocere" dictates avoiding substances with unproven safety during pregnancy when safer alternatives are available.
What do ACOG and WHO say about CBD in pregnancy?
The positions of scientific societies and health authorities are unequivocal in their caution.
ACOG (American College of Obstetricians and Gynecologists): In 2017, ACOG issued a statement advising against the use of marijuana and its derivatives — including CBD — during pregnancy and while breastfeeding. The ACOG statement indicates a lack of sufficient data on the safety of CBD in pregnant women and potential neurodevelopmental risks for the fetus. ACOG's recommendation is based on the principle of caution — not on proven harm, but on the lack of evidence of safety.
WHO: In its 2018 assessment, WHO recognized CBD as safe for adults at typical doses. However, the WHO assessment did not address pregnancy and breastfeeding — it constituted exceptional populations for which there is insufficient data. The lack of a specific WHO assessment for pregnant women does not mean that CBD is safe in pregnancy — it means that data is lacking.
Polish Society of Gynecologists and Obstetricians: The Polish recommendation is consistent with ACOG — avoid all cannabinoid products during pregnancy and while breastfeeding due to the lack of safety data for these populations. Treatment of pregnancy-related ailments (nausea, pain, insomnia, anxiety) should only occur under the supervision of a doctor using substances with a proven safety profile for pregnancy.
CBD and breastfeeding: what about breast milk?
The issue of breastfeeding is as important as pregnancy. CBD, like THC, passes into breast milk. Studies have shown that THC is detectable in the milk of nursing mothers for several weeks after cessation of use — due to the accumulation of lipophilic cannabinoids in fat tissue (from which they are slowly released into circulation and milk).
There is a lack of clinical data specifically for CBD in breast milk at supplemental doses. However, the pharmacokinetic properties of CBD (lipophilicity, long half-life, accumulation in fat tissue) suggest that CBD may also accumulate and pass into milk in significant amounts.
Why is this important? The endocannabinoid system of the infant is crucial for its proper neurological development during the first months of life. Exposure to external cannabinoids during this period may potentially modify the infant's ECS signaling in ways with unpredictable long-term consequences. There is no data indicating a specific risk — but there is also no data confirming safety. In the absence of certainty and with safe alternatives available, the recommendation to "avoid CBD while breastfeeding" is rational and consistent with the principle of medical caution.
Our observations: Women turning to CBD during pregnancy or breastfeeding often seek a natural alternative to medications — this is understandable and human. But "natural" does not mean "safe during pregnancy" — many natural substances (excess vitamin A, herbs like St. John's wort, star anise) are contraindicated during pregnancy. CBD has an unproven safety profile for pregnant women, making it a substance that requires the same caution as any untested drug.
Animal studies: what do we know about CBD and pregnancy from preclinical models?
Animal studies have allowed us to capture certain mechanisms of CBD action during pregnancy that cannot be ethically studied directly in humans. Their results are concerning — although they should be interpreted with the appropriate caution typical of animal models.
Study Campolongo et al. (Journal of Neuroscience, 2007) showed that prenatal exposure to cannabinoids disrupted the maturation of the endocannabinoid system in rats, with observable changes in CB1 receptor density in the hippocampus. These changes correlated with memory and learning impairments in adulthood. The study concerned THC, but since CBD indirectly modulates ECS signaling through FAAH and other targets, analogous effects of CBD remain hypothetically possible.
A study on a mouse model specifically analyzing CBD (not THC) showed altered expression of genes involved in neurogenesis in fetuses exposed to CBD from the mother. The doses used in the studies were generally higher than typical supplemental doses in humans — which is an important note for interpretation. But in the absence of clinical studies in humans, this preclinical data is the only warning signal we have.
Conclusions from preclinical studies: there is a biologically plausible mechanism for potential CBD risk to the developing fetus, although direct clinical data in humans is insufficient. It is not that "CBD is proven harmful during pregnancy" — it is that "we cannot assure that CBD is safe during pregnancy because we lack data."
CBD and common pregnancy ailments: what are the real alternatives?
Women turning to CBD during pregnancy usually have a specific reason — nausea, back pain, insomnia, or anxiety. Understanding that there are safe, tested alternatives for each of these ailments helps make an informed decision.
What instead of CBD during pregnancy? Safe alternatives
If you are using CBD for a specific health issue and are pregnant or breastfeeding, it is worth knowing what safe alternatives exist for specific ailments.
Nausea and vomiting in pregnancy: Ginger (tea, capsules) has well-documented effectiveness for pregnancy-related nausea and is classified as safe by most gynecological societies when used in reasonable amounts. Vitamin B6 (pyridoxine) 25–50 mg/day — first line in ACOG guidelines for pregnancy-related nausea. For severe vomiting — consult a doctor (doxylamine, ondansetron).
Pain and discomfort: Paracetamol is the only pain reliever recommended during pregnancy, used at the lowest effective dose for the shortest time. Ibuprofen and other NSAIDs are contraindicated after the 20th week of pregnancy. Physical therapy, prenatal exercises, massage by a certified prenatal massage therapist — safe and often effective non-pharmacological options.
Anxiety and sleep issues: Cognitive-behavioral therapy (CBT) is an effective method for anxiety and insomnia during pregnancy without any effects on the fetus. Breathing techniques, prenatal yoga, mindfulness. For heightened anxiety or prenatal depression — a psychiatrist who can safely prescribe medications with a documented safety profile in pregnancy.
Hemp seeds (hulled) are a form of hemp safe during pregnancy — they do not contain cannabinoids and are a rich source of omega-3 fatty acids, protein, and iron needed by pregnant women. Alpha-linolenic acid (ALA) from hemp seeds is a precursor to long-chain omega-3 fatty acids, important for the development of the brain and retina of the fetus.
Back pain and pelvic discomfort: Prenatal physical therapy is the first line for back pain and pelvic pain during pregnancy. A belly support belt, appropriate pillows for side sleeping, and pelvic floor strengthening exercises are effective non-pharmacological approaches. Prenatal massage by a certified massage therapist — effective for muscle pain. Paracetamol is the only safe pain reliever during pregnancy, used at the lowest effective dose and for the shortest necessary time.
When after pregnancy can you return to CBD?
After breastfeeding, if you want to return to CBD, you may consider it after consulting with a doctor — especially if you are taking medications postpartum (antidepressants, hormones, thyroid medications). CBD affects cytochrome P450 enzymes that metabolize many drugs, which can alter their concentrations in the blood.
CBD has a half-life of 18–32 hours — after a few days from the last dose, the concentration in the mother's body is negligible. With regular use, it may take several days to a week for CBD to completely disappear from tissues. If you want to ensure that breast milk is free of CBD, wait at least 5–7 days from the last dose before resuming breastfeeding (if you used CBD for a short time) or consult a doctor for long-term use.
At the same time, resuming CBD after pregnancy may be a reasonable step — CBD may be helpful for postpartum depression (through the 5-HT1A mechanism), postpartum anxiety, and sleep issues associated with caring for a newborn. Preliminary data suggest that CBD may reduce anxiety symptoms and improve sleep — and these issues are very common in the postpartum period. But before resuming — always consult with a doctor, especially if you are taking medications (antidepressants, hormonal medications). More about the safe use of CBD and drug interactions can be found in the article CBD for seniors – drug interactions.
Frequently Asked Questions
Is CBD safe during pregnancy?
There is insufficient data on the safety of CBD during pregnancy. ACOG (2017) recommend against all cannabinoids during pregnancy. CBD crosses the placental barrier (Bertrand et al., PMC, 2018) and may affect the fetal endocannabinoid system, which is crucial for its neurological development. Recommendation: do not use CBD during pregnancy.
Does CBD cross the placenta?
Yes. Bertrand et al. (PMC, 2018) they demonstrated the penetration of cannabinoids through the human placenta ex vivo. Concentrations on the fetal side are lower than on the maternal side, but CBD is detectable. It is unknown what concentrations of CBD in the fetus are biologically significant — and this uncertainty is a reason for caution.
Can CBD be used while breastfeeding?
We do not recommend it. CBD and THC pass into breast milk. The endocannabinoid system of the infant is crucial for its neurological development — exposure to cannabinoids through breast milk poses potential risks. There is a lack of safety data on CBD in breast milk at supplemental doses.
Is CBD for nausea during pregnancy safe?
We do not recommend it. Safer alternatives for pregnancy-related nausea include: ginger, vitamin B6 (after consulting with a doctor), and medications prescribed by a gynecologist. CBD has an unproven safety profile during pregnancy — with safe options available, there is no justification for the risk.
When can CBD be resumed after pregnancy and breastfeeding?
After breastfeeding is completed, following consultation with a doctor. CBD has a short half-life (18–32 hours) — after a few days from the last dose, it is negligible in the body. When resuming after childbirth, check for potential interactions with any medications taken postpartum.
This article is for informational and educational purposes and does not constitute medical advice. Before starting to use cannabis or CBD for therapeutic purposes, consult with a doctor, especially if you are taking other medications, are pregnant, or breastfeeding.
Author: Michał Waluk · Published: 2026-05-04 · Updated: 2026-05-04
