Illegal or recreational drugs and pregnancy

Taking illegal or recreational drugs during pregnancy can cause serious complications. There is support available to help you stop.

Using illegal, street or recreational drugs during pregnancy can have a serious effect on your unborn baby. This includes cannabis, ecstasy, cocaine and heroine.  

If you regularly use cocaine, heroin, or other similar drugs (opiates or opioids), do not stop or reduce the amount you take without speaking to a doctor first. It’s important to withdraw from these drugs in the right way to reduce the risk of problems for you and your baby. The safest way to quit is with medical help, as part of a drug treatment programme. 

It’s very important to be honest. They are there to help you have a safe and healthy pregnancy and will not judge you. 

Is it safe to take illegal drugs while I am pregnant? 

There are no illegal drugs that have been found to be safe in pregnancy, even in small amounts.  

There is clear evidence that some drugs are unsafe for your baby. Almost all drugs will pass through the placenta to reach your baby. So whatever you are taking, your unborn baby is taking too.   

Taking drugs (including tobacco and alcohol) when you are pregnant, even in small quantities, can put your baby’s health at serious risk. Drugs can also increase the risk of stillbirth or neonatal death.   

Your baby is also more likely to: 

If you stop using drugs (including tobacco and alcohol) you can reduce the risk of pregnancy complications.  

The best thing you can do for you and your baby is to avoid any taking any illegal drugs.  

What about prescribed medicines? 

You should also speak to your GP, midwife or drug support service if you are regularly taking prescribed medicines. Do not stop taking medication suddenly as this may be harmful for you and your baby. 

Read more about medicines in pregnancy

Should I tell my midwife about taking drugs? 

It can be difficult to tell your midwife or doctor about using drugs. You may be scared about their reaction, worried about the possibility of social services getting involved, or feeling anxious and guilty about the impact of drugs on your baby.  

But try to remember that getting support from a professional will help you. They are there to support you and make sure you and your baby are healthy, not to judge you. Try to remember that you are not alone – many people take drugs recreationally and your GP or midwife will have seen it all before.   

Try to think about pregnancy as a chance to change unsafe habits. Even if you are near the end of your pregnancy, it will still really benefit you and your baby if you are able to make changes.  

What if I took drugs before I knew I was pregnant? 

If you took a drug without realising you were pregnant on a one-off occasion, try not to worry – it is unlikely to have affected your baby. But if you regularly take illegal or recreational drugs, getting help can really make a difference. 

Whatever kind of drug you have taken, and however much you took, it is a good idea to mention it to your GP or midwife. They will be able to make sure you get any extra care that you may need during your pregnancy.  

What support can I get? 

There is a lot of support available to help you. Talk to your midwife or doctor about your situation. You can talk through what drugs you are taking, how often and how you feel. You should be offered a referral to a specialist midwife or doctor who can give you dedicated advice and offer you regular appointments. They will also be able to tell you about local services that could also help. You can also search for drug services in your area on the NHS website

Try to remember that specialist support services are private and confidential. The staff are there to listen to you and help you, without judgement. 

Your specialist midwife or doctor will talk with you about your antenatal care, any extra appointments or scans that may be needed, as well as any extra support your baby may need when they are born. In some cases you may be able to get for text message reminders and other practical help with getting to your appointments, such as transport. 

At these appointments, you should be able to talk about your feelings and worries. Your healthcare team will work with you to support you to have as healthy a pregnancy as possible. 

How can drugs affect my baby? 

If you use illegal or recreational drugs, it is important to know how they can affect your pregnancy and your baby. 

Cannabis (marijuana, dope, weed, skunk, grass, hash, pot, THC, CBD) 

Cannabis is the most widely used drug in the UK. There is evidence that using cannabis can trigger mental health issues, even if you have never experienced them before. It can also make any existing mental health issues worse. 

Cannabis also contains a substance called tetrahydrocannabinol (THC). Most cannabis found on the UK market has a very high level of THC.  

THC is known to cross the placenta and may affect your unborn baby’s development. Your baby is at increased risk of: 

  • being born prematurely 
  • being born with a low birthweight 
  • learning, behavioural and mental health issues as they grow up, including substance misuse). 

CBD (cannabidiol) has grown in popularity over the past few years and is found in food, drink, beauty product and supplements. However, it is not considered to be safe during pregnancy, even in creams or beauty products. This is because it is not clear whether any traces of the psychoactive ingredient (THC) are present in the products.  

More research is needed to understand the possible effects of CBD. But experts advise that you stay away from CBD oil products during pregnancy and breastfeeding.  

New psychoactive substances (sometimes called ‘legal highs’) such as MCAT, “bath salts” 

New psychoactive substances (so-called ‘legal highs’) are drugs that are created chemically. Although some of these so-called ‘legal highs’ were legal in the past, since the Psychoactive Substances Act came in 2016, none of these drugs are legal. 

As they are relatively new, there is very little research about them and their effects in pregnancy. It is thought that they have effects similar to ecstasy and crack cocaine.  

Cocaine and methamphetaime (“speed”) 

Cocaine (including crack cocaine) and methamphetamine (speed, or ice) are powerful stimulants that effect the central nervous system. 

Using these drugs during pregnancy may increase the risk of serious pregnancy complications such as: 

These drugs also cross the placenta and are absorbed by the baby. They reach the baby’s heart, brain and other organs. 

Ecstasy (MDMA) 

Ecstasy is absorbed into the bloodstream and is transferred across the placenta to the baby. One study has shown that heavy MDMA use in pregnancy is linked toassociated with poorer mental and motor development in infants at 12 months old. There is also some evidence to suggest that it can lead to an increased risk of baby having birth defects. However, this is limited research and we still don’t know the full effects of taking ecstasy during pregnancy.  

Heroin, strong painkillers and methadone 

Taking heroin when you’re pregnant causes serious risks for you and your baby. The same kind of problems can happen if you are regularly using strong painkillers (opiods), such as morphine or tramadol.  

Whether heroin is smoked or injected, it still enters the bloodstream and crosses over to your baby. Using heroin in pregnancy can cause the following complications. 

  • vaginal bleeding in the third trimester 
  • low birth weight 
  • baby suffering from withdrawal symptoms when born which can range from mild to life-threatening. Such symptoms can include sleep problems, irritability, seizures, tremors and problems feeding. 
  • sudden infant death syndrome. Find out more about safe sleep for babies

Women who inject heroin or other drugs may become infected with viruses such as HIV or Hepatitis B or C from dirty needles, and risk passing the virus on to their babies.


Ketamine may affect your baby’s brain, leading to problems with behaviour and mood as they grow. If you take ketamine close to your due date, your baby may have breathing problems after the birth. 

Neonatal abstinence syndrome (NAS) 

Some prescribed or illegal drugs that can cause physical dependency can pass through the placenta and be absorbed by your baby.  

After birth, your baby may show signs of physical withdrawal known as Neonatal Abstinence Syndrome. Some of these babies may need specialist care and medical treatment to help them withdraw.

If you have any questions about this, speak to your midwife.  

If someone close to you is taking drugs 

If your partner, your baby’s dad or someone close to you is taking drugs during your pregnancy, this can be worrying, stressful and difficult. They can also get support.  

Talk to your midwife or GP if you are worried about someone and think they may need help. 

More support 

You can contact FRANK for friendly, confidential drugs advice, including information on the different types of help available. 

The FRANK helpline is open every day, 24 hours a day on 0300 123 6600 or you can text them on 82111. 

NHS. Illegal drugs in pregnancy. (Page last reviewed: 9 May 2023 Next review due: 9 May 2026)

Behnke M, Smith VC; Committee on Substance Abuse; Committee on Fetus and Newborn. Prenatal substance abuse: short- and long-term effects on the exposed fetus. Pediatrics. 2013 Mar;131(3):e1009-24. doi: 10.1542/peds.2012-3931. Epub 2013 Feb 25. PMID: 23439891; PMCID: PMC8194464. 

NHS. Stop smoking in pregnancy. (Page last reviewed: 10 January 2023, Next review due: 31 January 2026)

Royal College of Obstetricians & Gynaecologists. Alcohol and pregnancy.

NICE (2010). Pregnancy and complex social factors (CG110) A model for service provision for pregnant women with complex social factors.

NHS Inform. Cannabis. (2022)

Royal Berkshire NHS Foundation Trust. Cannabis use in pregnancy. (May 2021 Next review due: May 2023)

US Food & Drink Administration (FDA). What You Should Know About Using Cannabis, Including CBD, When Pregnant or Breastfeeding. Available at:  

FRANK. New psychoactive substances.

Forray A. Substance use during pregnancy. F1000Res. 2016 May 13;5:F1000 Faculty Rev-887. doi: 10.12688/f1000research.7645.1. PMID: 27239283; PMCID: PMC4870985.

Singer, L. et. al. (2012). One-year outcomes of prenatal exposure to MDMA and other recreational drugs’, Pediatrics, 130(3), pp 407-413.

McElhatton, PR. (1999). ‘Congential anomalies after prenatal ecstasy exposure’, The Lancet, 354(9188), pp. 1441-1442. 

Minozzi S, et al. Maintenance agonist treatments for opiate dependent pregnant women. Cochrane Database Syst Rev. 2008 Apr 16;(2):CD006318. doi: 10.1002/14651858.CD006318.pub2. Update in: Cochrane Database Syst Rev. 2013;12:CD006318. PMID: 18425946.

NHS. Can HIV be passed to an unborn baby in pregnancy or through breastfeeding. (Page last reviewed: 27 May 2022 Net review due: 27 May 2025)

Zhao T, Li C, Wei W et al. 2016. Prenatal ketamine exposure causes abnormal development of prefrontal cortex in rat. Scientific Reports 6:26865 

BNF. nd. Ketamine. British National Formulary. 

Johnson K, et al. Treatment of neonatal abstinence syndrome. Archives of Disease in Childhood - Fetal and Neonatal Edition 2003;88:F2-F5.












Review dates
Reviewed: 13 June 2023
Next review: 13 June 2026