Macrolide antibiotics

Date: May 2020, Version 3.1

What are they?

The macrolides are a group of antibiotics used to treat a wide range of infections. Individual macrolides include azithromycin, clarithromycin, erythromycin, spiramycin and telithromycin.

Erythromycin is the most commonly prescribed macrolide during pregnancy. For specific information on erythromycin use, please see the bump leaflet on Use of erythromycin in pregnancy.

Little information is available on spiramycin and telithromycin with regard to pregnancy.


What are the benefits of using a macrolide in pregnancy?

Macrolides, in particular erythromycin, are used to treat infection and are commonly prescribed during pregnancy.


Are there any risks of using a macrolide during pregnancy?

There are no major concerns with use of macrolides (particularly erythromycin) in pregnancy. Overall, most studies are reassuring, and most doctors agree that the benefits to both mother and baby of treating infection outweigh any possible risks. 

Most studies of women who took macrolides provide no evidence of a link with birth defects in the baby. For the small number of studies that have found a possible link with birth defects, problems with the way in which the information was collected may have led to inaccurate analysis.

The majority of studies of women who took macrolides in early pregnancy also provide no evidence of a link with miscarriage.

There are no concerns that macrolides are linked to stillbirth, preterm birth or low birth weight. However, only small numbers of women have been studied for these outcomes.


Are there any alternatives to using a macrolide in pregnancy?

Possibly. Other types of antibiotic can be used in pregnancy. However, the choice of antibiotic will be based on the type of infection and whether you have had side effects from antibiotics in the past. If you have any questions about a medicine that you are offered in pregnancy, you should discuss them with your doctor or midwife.

No treatment

What if I prefer not to take medicines during pregnancy?

Treatment of infection during pregnancy is important. If left untreated, infection can make you and your baby seriously unwell. It is therefore important to take antibiotics that have been prescribed for you. You can feel reassured that these medicines are commonly used. Your doctor will only prescribe medicines when absolutely necessary and will be happy to talk to you about any concerns that you might have.

Will my baby need extra monitoring?

As part of their routine antenatal care most women will be offered a detailed scan at around 20 weeks of pregnancy to check the baby’s wellbeing.
Taking a macrolide during pregnancy is not expected to cause any problems that would require extra monitoring of your baby. 

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

We would not expect any increased risk to your baby if the father took a macrolide before or around the time you became pregnant.

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

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.