(Date: October 2016. Version: 2)

This factsheet has been written for members of the public by the UK Teratology Information Service (UKTIS). UKTIS is a not-for-profit organisation funded by the UK Health Security Agency (UKHSA) on behalf of UK Health Departments. UKTIS has been providing scientific information to health care providers since 1983 on the effects that medicines, recreational drugs and chemicals may have on the developing baby during pregnancy.

What is it?

Ecstasy (MDMA) is a recreational drug that causes hallucinations and changes in mood and behaviour by affecting the balance of certain chemicals in the brain.

Is it safe to use ecstasy during pregnancy?

Use of ecstasy in pregnancy in not advised. When a pregnant woman uses ecstasy it enters her bloodstream and crosses the placenta to the baby. The effects on a developing baby from ecstasy exposure are unclear as very few pregnant women who took ecstasy have been studied. Some studies suggest that use of ecstasy in pregnancy might harm a baby in the womb. Additionally, ecstasy is rarely available in pure form and is often mixed with a combination of other drugs which may themselves be harmful to both the mother and her unborn child. There are also a number of related drugs that are often sold as ecstasy. The risks of taking a substance that is being sold as ‘ecstasy’ are therefore very uncertain. 

What if I have already used ecstasy during pregnancy?

If you are pregnant and use ecstasy you should speak to your doctor or midwife about this. They will be able to get you help and support to safely stop using ecstasy.

Can using ecstasy during pregnancy cause birth defects?

A baby’s body and most internal organs are formed during the first 12 weeks of pregnancy. It is mainly during this time that exposure to recreational drugs could potentially cause birth defects.

MDMA causes narrowing of the blood vessels resulting in reduced blood flow. There have therefore been concerns that use of ecstasy in pregnancy may cause birth defects, such as gastroschisis (see below), that are due to abnormal blood flow during the development of a baby in the womb.

Two small studies of a total of 170 pregnant women who used ecstasy did not suggest that they were more at risk of having a baby with a birth defect overall, but were not able to rule out a link with a specific birth defects. However, two studies which specifically investigated a link with a birth defect called gastroschisis (where the baby’s abdominal organs protrude outside the body through a hole beside the belly button) found a possible link to use of recreational drugs such as ecstasy in early pregnancy.

Because very few pregnant women taking ecstasy have been studied, more research is required to determine whether ecstasy use in pregnancy can cause birth defects in the baby.

Can using ecstasy in pregnancy cause miscarriage?

Miscarriage rates have been studied in a total of 170 women who used ecstasy in early pregnancy. Although there was no evidence of miscarriage being more likely following ecstasy use, many more pregnant women need to be studied before we can say that use of ecstasy does not increase the risk of miscarriage. 

Can using ecstasy in pregnancy cause stillbirth?

No studies have assessed stillbirth rates in pregnant women taking ecstasy. However, because ecstasy affects the blood vessels and reduces blood flow, there is a theoretical concern that its use in pregnancy could increase the risk of stillbirth.

Can using ecstasy in pregnancy cause low birth weight?

There is a theoretical concern that use of ecstasy in pregnancy could increase the risk of low birth weight in the baby as a result of reduced blood flow to the baby. A very small study of 28 babies exposed to ecstasy in the womb showed that they had similar birth weights to babies exposed in the womb to other recreational drugs. However, birth weights of many more babies exposed in the womb to ecstasy need to be compared to the birth weights of babies born to women not taking recreational drugs before we can say whether ecstasy use in pregnancy might affect a baby’s weight.

Can using ecstasy in pregnancy cause premature delivery (<37 weeks)?

Premature delivery rates have been studied in 164 babies exposed in the womb to ecstasy. Although there is currently no suggestion that use of ecstasy in pregnancy increases the risk of premature delivery, many more pregnant women who used ecstasy need to be studied to confirm this finding.

Can using ecstasy in pregnancy cause withdrawal symptoms in the newborn baby?

Because ecstasy affects the balance of certain chemicals in the brain, heavy users can experience withdrawal symptoms. However, no studies have addressed whether exposure to ecstasy in the days and weeks before delivery can lead to withdrawal symptoms (such as jitteriness, increased muscle tone, and high-pitched screaming) in the newborn baby.

Because there is a theoretical possibility that the baby may experience withdrawal symptoms, if you have regularly used ecstasy in pregnancy, or if you have taken ecstasy around the time of delivery, it is important that you tell your doctor or midwife. They may advise that your baby is born in a unit that can monitor and treat your baby for withdrawal symptoms if necessary.

Can using ecstasy in pregnancy cause learning or behavioural problems in the child?

A baby’s brain continues to develop right up until the end of pregnancy. It is therefore possible that exposure to certain substances at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour.

Ecstasy affects the balance of ‘mood chemicals’ in the brain. There are therefore concerns that using ecstasy during pregnancy could also affect an unborn baby’s developing brain.

One small study of 25 two year old children exposed to ecstasy in the womb showed that their motor skills were poorer than those of children exposed in the womb to other recreational drugs. In this study, behaviour, memory, language, problem solving abilities and coordination were similar between the two groups. Larger studies of children exposed in the womb to ecstasy are required to confirm these findings, and the children in this study will need to be assessed as they get older to see if they ‘grow out’ of any problems with motor skills, or whether problems with their learning or behaviour become apparent once they are at school.

Will my baby need extra monitoring during pregnancy?

As part of their routine antenatal care most women will be offered a scan at around 20 weeks of pregnancy to look for birth defects and to check the baby’s growth.

If you have used ecstasy during pregnancy it is best for you and your baby that you tell your doctor or midwife as soon as possible. They will then be able to make sure that you and your baby receive extra monitoring or support if necessary. 

Are there any risks to my baby if the father uses ecstasy?

No studies have specifically investigated whether ecstasy used by the father can harm the baby through effects on the sperm, however most experts agree that this is very unlikely. More research on the effects of drug and medicine use in men around the time of conception is needed.

Who can I talk to if I have questions?

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

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General information 

Up to 1 out of every 5 pregnancies ends in a miscarriage, and 1 in 40 babies are born with a birth defect. These are referred to as the background population risks.  They describe the chance of these events happening for any pregnancy before taking factors such as the mother’s health during pregnancy, her lifestyle, medicines she takes and the genetic make up of her and the baby’s father into account.

Medicines use in pregnancy

Most medicines used by the mother will cross the placenta and reach the baby. Sometimes this may have beneficial effects for the baby.  There are, however, some medicines that can harm a baby’s normal development.  How a medicine affects a baby may depend on the stage of pregnancy when the medicine is taken. If you are on regular medication you should discuss these effects with your doctor/health care team before becoming pregnant.

If a new medicine is suggested for you during pregnancy, please ensure the doctor or health care professional treating you is aware of your pregnancy.

When deciding whether or not to use a medicine in pregnancy you need to weigh up how the medicine might improve your and/or your unborn baby’s health against any possible problems that the drug may cause. Our bumps leaflets are written to provide you with a summary of what is known about use of a specific medicine in pregnancy so that you can decide together with your health care provider what is best for you and your baby.   

Every pregnancy is unique. The decision to start, stop, continue or change a prescribed medicine before or during pregnancy should be made in consultation with your health care provider. It is very helpful if you can record all your medication taken in pregnancy in your hand held maternity records.

Disclaimer: This information is not intended to replace the individual care and advice of your health care provider. New information is continually becoming available. Whilst every effort will be made to ensure that this information is accurate and up to date at the time of publication, we cannot cover every eventuality and the information providers cannot be held responsible for any adverse outcomes following decisions made on the basis of this information. We strongly advise that printouts should NOT be kept for any length of time, or for “future reference” as they can rapidly become out of date.

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