Macrolides

THE SAFETY OF MACROLIDES DURING PREGNANCY OR BREASTFEEDING

The information provided below is for readers based in the United States of America. Readers outside of the United States of America should seek the information from local sources.

THIS MEDICATION CAN CAUSE HARM TO YOUR BABY:

The use of macrolides during pregnancy may increase the risk of some birth defects and health problems in your baby. These medications may also increase the risk that your baby will develop functional impairments, epilepsy, or cerebral palsy. Macrolides should be avoided during pregnancy unless medically necessary.

What are macrolides?

Macrolides are types of antibiotics used to treat infections caused by bacteria. These medications are available as oral tablets or capsules, oral liquids, or intravenous (IV) solutions that are injected into a vein in your arm by a healthcare professional. Types of macrolide antibiotics that are available include: azithromycin (Zithromax), erythromycin (Ery-Tab), clarithromycin (Biaxin), and fidaxomicin (Dificid). These medications are only available by prescription from your doctor.

What are macrolides used to treat?

Macrolides are used to treat bacterial infections. They are effective against a wide range of infections, including sinus, respiratory, ear, skin, sexually transmitted, and digestive tract infections.

How do macrolides work?

Macrolides prevent the growth and development of bacteria by preventing them from producing substances that are necessary for their survival.

If I am taking a macrolide, can it harm my baby?

The FDA has indicated that azithromycin, erythromycin, and fidaxomicin should only be used during pregnancy if medically necessary. Clarithromycin should not be used during pregnancy unless no alternative antibiotics are appropriate. There has been some evidence that macrolides taken during pregnancy may increase the risk of birth defects in the heart and other health problems. However, other studies did not find an increased risk for these birth defects when macrolides were taken during pregnancy.

Evidence:

A study looked at 1,844 babies whose moms used erythromycin early in pregnancy. They found that erythromycin was associated with a higher risk of birth defects in the heart and pyloric stenosis. Pyloric stenosis is a condition involving the baby’s stomach and small intestine, which can lead to forceful vomiting.

A study looked at 764 expecting moms who took erythromycin and 755 expecting moms who took erythromycin in addition to another antibiotic. This study found that taking erythromycin during pregnancy increased the risk that the baby would be born with a functional impairment, such as a problem with eyesight, hearing, speech, movement, or brain function. They also found that babies whose mom used erythromycin during pregnancy had an increased risk of developing cerebral palsy, a condition caused by brain damage that leads to problems with movement and muscle tone. Another study found that the use of macrolides during pregnancy increased the risk of cerebral palsy and epilepsy in babies.

Despite some studies showing that macrolides taken during pregnancy increase the risk of birth defects and other health problems in babies, there are other studies that did not find this increased risk. One study looked at 1,033 expecting moms who took a macrolide during the first trimester of pregnancy. They found no association between macrolides and birth defects. They also looked at 959 expecting moms who took a macrolide during the third trimester of pregnancy and found no increased risk of premature birth, low birth weight, or miscarriage. Another study that looked at 1,786 expecting moms who took erythromycin during the first trimester of pregnancy did not find an increased risk of birth defects in the heart. Furthermore, a study that looked at data from the Slone Epidemiology Center Birth Defects Study did not find an increased risk of birth defects in the heart or pyloric stenosis when macrolides were taken during pregnancy.

Bottom line: Macrolides should not be used during pregnancy unless medically necessary. There have been some studies which showed that the use of macrolides during pregnancy increased the risk of birth defects. Several other studies have shown that these medications can increase the risk that your baby will develop functional impairments, cerebral palsy, or epilepsy.

If I am taking a macrolide and become pregnant, what should I do?

If you become pregnant while taking a macrolide, you should contact your doctor immediately. Your doctor may decide to discontinue your medication until after the birth of your baby.

If I am taking a macrolide, can I safely breastfeed my baby?

The FDA advises that caution should be used if macrolide antibiotics are used while breastfeeding. Macrolides pass into breast milk and may cause harm to your baby. Although the American Academy of Pediatrics has categorized erythromycin as usually compatible with breastfeeding, some later studies have found that taking these medications while nursing can cause health problems in babies. A study concluded that there is an increased risk of pyloric stenosis in babies whose moms take macrolides while breastfeeding. Another study did not find an increased risk of pyloric stenosis in babies whose mom took a macrolide while breastfeeding. However, they did find that some babies exposed to a macrolide through breast milk experienced diarrhea, loss of appetite, rash, and sleepiness.

Bottom line: Macrolides should be used with caution while breastfeeding. Your doctor will determine if a macrolide is medically necessary. Some studies have reported a higher risk of pyloric stenosis in babies whose mom took a macrolide while nursing.

If I am taking a macrolide, will it be more difficult to get pregnant?

There have been no studies demonstrating changes in fertility in men or women who take macrolides. Antibiotics can sometimes cause oral contraceptives to be less effective. You should contact your doctor prior to taking macrolides with oral contraceptives because a back-up contraceptive method may be required.

If I am taking a macrolide, what should I know?

Macrolides should be avoided during pregnancy unless medically necessary. Some studies have found an increased risk of birth defects in the heart and other health problems in babies whose mom took a macrolide during pregnancy. There have also been some studies showing that taking a macrolide while pregnant can increase the risk that your baby will develop functional impairments, epilepsy, or cerebral palsy.

Macrolides should be used with caution while breastfeeding. Some studies have shown that babies have a higher risk of pyloric stenosis when moms take these medications while nursing.

If I am taking any medication, what should I know?

This report provides a summary of available information about the use of macrolides during pregnancy and breastfeeding. Content is from the product label unless otherwise indicated.

You may find Pregistry's expert reports about individual infections here.  Additional information can also be found in the links below. 

Resources for macrolides during pregnancy and breastfeeding:

For more information about macrolides during and after pregnancy, contact http://www.womenshealth.gov/ (800-994-9662 [TDD: 888-220-5446]) or check the following links:

UpToDate (2017):Azithromycin, clarithromycin, and telithromycin

Merck Manual (2015): Macrolides

Read the whole report
General information

It is very common for women to worry about having a miscarriage or giving birth to a child with a birth defect while they are pregnant. Many decisions that women make about their health during pregnancy are made with these concerns in mind.

For many women these concerns are very real. As many as 1 in 5 pregnancies end in a miscarriage, and 1 in 33 babies are born with a birth defect. These rates are considered the background population risk, which means they do not take into consideration anything about the health of the mom, the medications she is taking, or the family history of the mom or the baby’s dad. A number of different things can increase these risks, including taking certain medications during pregnancy.

It is known that most medications, including over-the-counter medications, taken during pregnancy do get passed on to the baby. Fortunately, most medicines are not harmful to the baby and can be safely taken during pregnancy. But there are some that are known to be harmful to a baby’s normal development and growth, especially when they are taken during certain times of the pregnancy. Because of this, it is important to talk with your doctor or midwife about any medications you are taking, ideally before you even try to get pregnant.

If a doctor other than the one caring for your pregnancy recommends that you start a new medicine while you are pregnant, it is important that you let them know you are pregnant.

If you do need to take a new medication while pregnant, it is important to discuss the possible risks the medicine may pose on your pregnancy with your doctor or midwife. They can help you understand the benefits and the risks of taking the medicine.

Ultimately, the decision to start, stop, or change medications during pregnancy is up to you to make, along with input from your doctor or midwife. If you do take medications during pregnancy, be sure to keep track of all the medications you are taking.