Cannabis in Pregnancy: Is It Safe? Guide
It's natural to have questions about how lifestyle choices might affect your baby once you find out you're pregnant. This guide sets out the current UK guidance on cannabis use in pregnancy in plain language, so you can make an informed decision and know where to turn for support.
What the Evidence Says
Cannabis crosses the placenta, and THC — its main active ingredient — can reach your baby's developing brain and body. Because of this, UK guidance is clear that the safest choice in pregnancy is to avoid cannabis altogether.
- Research links cannabis use in pregnancy to lower birth weight and a higher chance of premature birth.
- Some evidence points to possible effects on attention, learning and behaviour later in childhood, though research in this area is still developing.
- Modern cannabis is often significantly stronger than cannabis from decades ago, so older reassurances about "occasional use" don't necessarily apply today.
- There is no known safe amount of cannabis use in pregnancy, in the same way there is no known safe amount of alcohol.
Medical Cannabis, CBD and Using Cannabis for Symptoms
Not every situation is the same, and it helps to know the distinctions.
- Prescribed medical cannabis — if you've been prescribed medical cannabis for a specific condition, don't stop suddenly without speaking to the specialist who prescribed it. They can weigh up the risks and benefits with you and adjust your care plan safely.
- Over-the-counter CBD products — these are not well studied in pregnancy, quality and content can vary between brands, and some products contain more THC than labelled. They are not recommended in pregnancy.
- Using cannabis to manage nausea, anxiety or sleep problems — this is common, but safer, evidence-based alternatives exist for all of these symptoms. Your midwife or GP can offer effective options without judgement.
Getting Support to Stop
If you're using cannabis and have just found out you're pregnant, try not to panic — reaching out for help now is one of the most positive steps you can take for your baby.
- Your midwife or GP can talk you through safe ways to stop and connect you with local support services.
- If you use cannabis alongside tobacco, quitting both together is especially important, and NHS stop-smoking services can help with the nicotine side.
- Local drug and alcohol services offer confidential support and are used to working with pregnant women — you will not be judged.
- Counselling and peer support groups can help address the reasons behind use, not just the habit itself.
Frequently Asked Questions
Is cannabis safe to use during pregnancy?
No. UK guidance advises against any cannabis use in pregnancy because THC crosses the placenta and can affect your baby's development. If you've used cannabis before finding out you were pregnant, speak to your midwife or GP for reassurance and support rather than worrying alone.
Is CBD oil safe in pregnancy?
CBD products are not well regulated or studied in pregnancy, and some contain more THC than the label states. They are not recommended, so it's best to avoid CBD products until after pregnancy and breastfeeding.
How can I get help to stop using cannabis while pregnant?
Speak confidentially to your midwife, GP, or a local drug and alcohol service — all can offer support without judgement. If tobacco is also involved, NHS stop-smoking services can help you quit both at the same time.
This article is for general information only and does not replace advice from your midwife or GP.
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