(Date: November 2018. Version: 1)

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?

Xonvea® is a medicine that is used to treat nausea and vomiting in pregnancy. It is taken as a tablet and contains an antihistamine called doxylamine, as well as vitamin B6.

Is it safe to take Xonvea® in pregnancy?

Xonvea® is licensed for use in pregnant women. Studies have shown that Xonvea® does not cause birth defects in the baby; however other potential effects of this medicine have not been well studied. This leaflet summarises all of the available information on pregnant women who have taken medicines with the same active ingredients as Xonvea®.

Can taking Xonvea® cause miscarriage?

There are no well-designed studies to investigate the risk of miscarriage following use of Xonvea® in early pregnancy.

Can taking Xonvea® in pregnancy cause my baby to be born with 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 some medicines are known to cause birth defects.

Studies of thousands of pregnant women taking medicines with the same active ingredients as Xonvea® provide no proof of a link with birth defects in the baby.

Can taking Xonvea® in pregnancy cause stillbirth?

No studies have investigated the chance of stillbirth following use of Xonvea® in pregnancy.

Can taking Xonvea® in pregnancy cause preterm birth or my baby to be small at birth (low birth weight)?

A small study raised no concerns that exposure in early pregnancy to medicines with the same active ingredients as Xonvea® affects the chance of preterm birth or the baby’s birth weight. Larger studies are required to confirm these findings.

Can taking Xonvea® 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 taking certain medicines at any stage of pregnancy could have a lasting effect on a child’s learning or behaviour.

Two small studies assessed the learning and behaviour of children aged up to seven years who had been exposed  in the womb to medication with the same ingredients as Xonvea®. Although no problems were noted, much larger studies that investigate many more aspects of learning and behaviour are required to confirm these findings.

Will I or my baby need extra monitoring during pregnancy?

Most women will be offered a scan at 20 weeks of pregnancy to look for birth defects as part of their routine antenatal care. Use of Xonvea® in early pregnancy is not expected to cause any problems that would require additional scanning.

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 healthcare provider. They can access more detailed medical and scientific information from www.uktis.org

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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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