Recreational drugs

Date: March 2026, Version 1.0

Quick read

Recreational drugs are not recommended in pregnancy as it is not clear how they might affect the developing baby.

What are they?

Common recreational drugs include cannabis, cocaine, heroin, amphetamines, MDMA, LSD, khat, synthetic cathinones, synthetic cannabinoids, kratom, ketamine, GHB, and nitrous oxide. Some prescription medicines are also used recreationally, such as benzodiazepines, some opioid painkillers, and gabapentin.

What are the risks of using recreational drugs in pregnancy?

There is no good information of the effects of synthetic cathinones, synthetic cannabinoids, kratom, GHB and nitrous oxide in pregnancy, and it is unknown how they might affect the baby. For most other recreational drugs, the effects of use during pregnancy are not well known, but could include:

Birth defects. Some studies suggest that using cannabis, cocaine, amphetamines, LSD, or khat in the first trimester increases the risk of birth defects in babies. Not all studies agree with these findings and so the level of risk is unclear.

Prematurity and low birth weight. Exposure to cannabis, cocaine, heroin, and amphetamines has been linked to preterm birth and low infant birth weight. Using tobacco with recreational drugs is common (particularly smoking tobacco and cannabis together) and may contribute to these outcomes.

Effects on the placenta. Cocaine, amphetamines, and MDMA can affect blood flow to the placenta. This could lead to the baby receiving less oxygen and might increase the risk of some birth defects that are caused by reduced blood flow. Cocaine exposure has also been linked to placental abruption.

Withdrawal symptoms in the newborn baby. Babies exposed to heroin and other opioids (such as fentanyl, oxycodone, and morphine) around the time of delivery are at high risk of withdrawal symptoms after birth. This often requires hospital treatment.

Sudden infant death syndrome (SIDS). Babies who were exposed in the womb to recreational drugs may be at higher risk of SIDS. It is unclear whether factors after birth may also contribute to this risk.

Learning and behavioural issues. Use of some recreational drugs (including cannabis, cocaine, heroin, amphetamines, and MDMA) has been linked to altered learning and behaviour in children who were exposed in the womb. Some drugs have also been linked to a higher risk of ADHD and autism. It is unclear whether these risks are due to drug exposure in pregnancy, or whether other factors after birth also contribute.

What if I have already taken a recreational drug during pregnancy?

Occasional use - it is recommended that you avoid any further exposure and speak to your doctor or midwife about whether you might need any extra pregnancy monitoring.

Regular use - if you feel like you cannot stop using recreational drugs, please speak to your doctor who may recommend an assisted withdrawal programme. For some types of drug (e.g. heroin) it can be dangerous to both you and your baby to stop suddenly.

It is also important that if you smoke tobacco, you should stop during pregnancy or cut down as much as possible. Your doctor or midwife will be able to help with this and may prescribe nicotine replacement therapy.

Will I or my baby need extra monitoring?

As part of routine antenatal care, most women will be offered a very detailed scan at around 20 weeks of pregnancy to check the baby’s development.

Depending on the drug used and the stage of pregnancy, you might be offered your 20-week scan from around 16 weeks onwards. Women who have used drugs in later pregnancy or who are on an assisted withdrawal programme may be offered extra monitoring, including of their baby’s growth.

Are there any risks to my baby if the father has taken a recreational drug?

There is very little information about whether drugs used by the father could harm the baby through effects on the sperm, but this is generally considered unlikely.

Who can I talk to if I have questions?

If you have any questions about the information in this leaflet, please discuss them with your health care provider. They can access more detailed medical and scientific information from www.uktis.org.

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.