(Date: May 2017. 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 LSD?

LSD is a recreational drug that causes hallucinations and changes in mood and behaviour.

Is it safe to use LSD during pregnancy?

LSD use in pregnancy is not advised. When a pregnant woman uses LSD it enters her bloodstream and crosses the placenta to the baby. There is very little high quality scientific information on the effects that LSD use in pregnancy might have on a developing baby’s health or brain. The little information that is available suggests that LSD use may be harmful to a pregnancy.

What if I have already used LSD during pregnancy?

If you are pregnant and use LSD you should speak to your doctor or midwife about this. They will be able to advise you on getting help and support to stop using LSD.

Can using LSD 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.

It is currently unclear whether use of LSD in pregnancy might cause birth defects in the baby as no well-designed studies have been carried out. There are case reports of a number of babies with limb or brain defects being born to mothers who used LSD in pregnancy but it is unclear whether the defects in the baby were linked to LSD use during pregnancy or occurred due to other factors.

Can using LSD in pregnancy cause miscarriage?

It is currently unclear whether use of LSD in pregnancy might cause miscarriage as no well-designed studies have been carried out to investigate this. Scientific reports have suggested that women who use LSD in early pregnancy may be more likely to miscarry than women who do not, but further research is required to determine whether this is the case.

Can using LSD in pregnancy cause stillbirth?

No studies have investigated the chance of stillbirth in women who use LSD in pregnancy.

Can using LSD in pregnancy cause premature birth, or low birth weight in the baby?

No studies have investigated the chance of premature birth (<37 weeks) or low birth weight (<2,500 g) in babies born to women who use LSD in pregnancy.

Can using LSD 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.

Because LSD affects mood and behaviour there are theoretical concerns that it might have effects on a baby’s developing brain that could cause lifelong difficulties. However, learning and behaviour of children who have been exposed to LSD in the womb has not been studied and it is therefore not possible to measure how big any risk might be.

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 LSD 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 used LSD?

No studies have specifically investigated whether LSD used by the father can harm the baby through effects on the sperm. 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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