Ondansetron
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Ondansetron can be used to treat pregnancy sickness that is stopping you from living your normal life.
What is it?
Ondansetron (Zofran®) is an anti-sickness medicine that can help with nausea (feeling sick) and vomiting (being sick).
For general information, please see the Bump leaflet on treatment of nausea and vomiting in pregnancy.
Benefits
What are the benefits of taking ondansetron in pregnancy?
Ondansetron can work very well to treat nausea and vomiting and can help with severe pregnancy sickness (known as hyperemesis gravidarum). It often works when other medicines have not helped and might be used at the same time as other anti-sickness drugs.
Good treatment for pregnancy sickness can help you to feel better and allow you to carry out your everyday activities. Treatment can prevent complications from nausea and vomiting, including dehydration (when you don’t have enough water in your body), because you can’t drink normally or if you are being sick a lot.
Risks
Are there any risks of taking ondansetron during pregnancy?
Some studies have suggested that heart defects and cleft lip and palate may be slightly more common in babies exposed to ondansetron in early pregnancy. It is clear that these risks are very low, and most babies exposed in the womb to ondansetron do not have these birth defects. Ondansetron used from around week 11 of pregnancy would not be able to cause these problems as at this stage as the baby is fully developed.
There are no concerns that ondansetron use in pregnancy affects the chance of miscarriage, stillbirth, preterm delivery or low infant birth weight.
Alternatives
Are there any alternatives to taking ondansetron?
Possibly. Other medicines can be used to treat pregnancy sickness but might not work as well as ondansetron.
No treatment
What if I prefer not to take ondansetron during pregnancy?
If your doctor has suggested that you take ondansetron, this is because your pregnancy sickness is preventing you from living your life and might be affecting your physical and/or mental health. You can decide together with your doctor whether taking ondansetron is right for you.
If you cannot eat normally, are struggling to keep drinks down, or are vomiting up medicines that you need to take, it is important to get the right anti-sickness treatment. Severe vomiting can cause you to become dehydrated and very unwell. Using ondansetron can help some women avoid hospital treatment for dehydration.
Will my baby need extra monitoring?
All pregnant women in the UK should be offered a very detailed anomaly scan at around 20 weeks of pregnancy as part of their routine antenatal care. No extra monitoring for major birth defects is required following ondansetron use in pregnancy.
Who can I talk to if I have questions?
If you have any questions relating to 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.
The charity Pregnancy Sickness Support provides resources, information and advice for women experiencing hyperemesis gravidarum.