Erythromycin

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Date: February 2026, Version 4.0

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It is important to correctly treat an infection. Erythromycin can be used in pregnancy if recommended by a doctor.

What is it?

Erythromycin (Erythrocin®) is used to treat a wide range of infections and is commonly prescribed during pregnancy.

Benefits

What are the benefits of using erythromycin in pregnancy?

Erythromycin can treat many types of infection and prevent serious complications to both you and your baby.

Risks

What are the risks of using erythromycin in pregnancy?

There are no concerns that use of erythromycin in pregnancy will harm your baby.

Alternatives

Are there any alternatives to taking erythromycin in pregnancy?

Possibly, although alternative antibiotics may not work as well for some types of infection. If erythromycin is recommended, a doctor will be able to discuss why it is the best treatment.

No treatment

What if I prefer not to take medicines in pregnancy?

It is important that an infection in pregnancy is well-treated. Untreated infections can make you feel unwell and can lead to very unpleasant symptoms, as well as serious complications for both you and your baby.

A doctor will only prescribe medicines when necessary and will be happy to talk about any concerns.

Will I or my baby need extra monitoring?

As part of routine antenatal care, most women will be offered a very detailed scan at around 20 weeks of pregnancy to check the baby’s development. No extra monitoring for major birth defects is required following use of erythromycin.

Are there any risks to my baby if the father has taken erythromycin?

There is no evidence that erythromycin used by the father can harm your baby through effects on the sperm.

Who can I talk to if I have questions?

If you have any questions about 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.

How can I help to improve drug safety information for pregnant women in the future?

Our online reporting system (MyBump Portal) allows women who are currently pregnant to create a secure record of their pregnancy, collected through a series of questionnaires. You will be asked to enter information about your health, whether or not you take any medicines, your pregnancy outcome and your child's development. You can update your details at any time during pregnancy or afterwards. This information will help us better understand how medicines affect the health of pregnant women and their babies. Please visit the MyBump Portal to register.

General information
Sadly, miscarriage and birth defects can occur in any pregnancy.

Miscarriage occurs in about 1 in every 5 pregnancies, and 1 in every 40 babies are born with a birth defect. This is called the ‘background risk’ and happens whether medication is taken or not.

Most medicines cross the placenta and reach the baby. For many medications this is not a problem. However, some medicines can affect a baby’s growth and development.

If you take regular medication and are planning to conceive, you should discuss whether your medicine is safe to continue with your doctor/health care team before becoming pregnant. If you have an unplanned pregnancy while taking a medicine, you should tell your doctor as soon as possible.

If a new medicine is suggested for you during pregnancy, please make sure that the person prescribing it knows that you are pregnant. If you have any concerns about a medicine, you can check with your doctor, midwife or pharmacist.

Our Bumps information leaflets provide information about the effects of medicines in pregnancy so that you can decide, together with your healthcare provider, what is best for you and your baby.