Cannabis in Pregnancy: Complete Guide
Whether you used cannabis before finding out you were pregnant, or you're wondering how risky it really is, you deserve clear, non-judgemental information — not scare tactics. Here's what's currently understood, and how to get support if you need it.
Why cannabis isn't considered safe in pregnancy
THC, the main psychoactive compound in cannabis, crosses the placenta and reaches your baby. Because a developing baby's brain and body are growing rapidly, exposure to THC during this period is a concern. Current NHS guidance advises against using cannabis at any point during pregnancy or while trying to conceive.
What the concerns are
- Brain development: cannabis use in pregnancy has been associated with effects on fetal brain development.
- Birth weight: babies exposed to cannabis in the womb are more likely to be born smaller than expected.
- Stillbirth risk: cannabis use has been associated with an increased risk of stillbirth.
- Long-term effects: some research points to possible effects on attention, learning and behaviour later in childhood, though this is an area of ongoing study.
Smoking cannabis also carries the same risks as smoking tobacco — including exposure to carbon monoxide and other harmful substances — which adds an additional layer of risk on top of the THC exposure itself.
What about CBD?
CBD (cannabidiol) products are widely available and marketed as non-intoxicating, but that doesn't automatically make them safe in pregnancy. Safety data specifically in pregnant women is limited, and over-the-counter CBD products aren't regulated to the same standard as medicines — meaning what's actually in them, including THC traces, isn't always reliable. The safest approach is to avoid CBD in pregnancy unless it's been specifically prescribed by a doctor for a medical reason.
If you use cannabis — talk to your midwife or GP
This is genuinely one of the most important messages here: your midwife and GP are there to support you, not to judge you. Being open about cannabis use means they can give you accurate advice, monitor your pregnancy appropriately, and connect you with specialist support to help you cut down or stop if that's what you want. Hiding it out of fear of judgement only removes their ability to help you and your baby.
Getting support
If you'd like help stopping or cutting down, FRANK offers free, confidential drug advice and can point you towards local support services — you can call 0300 123 6600. Your GP or midwife can also refer you to specialist maternity substance support services, which exist specifically to help pregnant women without judgement.
Frequently Asked Questions
Is cannabis safe in pregnancy?
No — current guidance advises against cannabis use at any point in pregnancy. THC crosses the placenta and reaches your baby, and use has been linked to effects on brain development, lower birth weight, and increased stillbirth risk. If you've used cannabis, speak to your midwife so they can support you appropriately.
Can I use CBD in pregnancy?
It's best avoided unless specifically prescribed by a doctor. Safety data on CBD in pregnancy is limited, and unregulated over-the-counter products can vary in what they actually contain, including trace THC. Speak to your GP if you're considering CBD for a medical reason.
Will my midwife judge me or report me for using cannabis?
Midwives and GPs are there to support your health and your baby's health, not to judge you. Being honest allows them to give you accurate, personalised advice and connect you with specialist help if you want it. Confidentiality and safeguarding policies vary by circumstance, so if you have specific concerns, it's worth asking your midwife directly how information is handled.
This article is for informational purposes only and does not constitute medical advice.
Related articles: