Is erythromycin safe during pregnancy?
Answered by MotherToBaby’s teratology specialists, quoted in full — including the questions most pages skip, like whether a father’s exposure matters.
The questions people actually ask about erythromycin in pregnancy
Answered by MotherToBaby, the fact sheets written by the Organization of Teratology Information Specialists and published through the NIH. Quoted in full — we do not condense them.
I take erythromycin. Can it make it harder for me to get pregnant?
Studies have not been done to see if taking erythromycin can make it harder to get pregnant.
Does taking erythromycin increase the chance for miscarriage?
Miscarriage is common and can occur in any pregnancy. It is not known if erythromycin increases the chance for miscarriage. However, studies that have looked at erythromycin and the chance for birth defects have not reported a higher rate of miscarriage.
Does taking erythromycin increase the chance of birth defects?
Every pregnancy starts out with a 3-5% chance of having a birth defect. This is called the background risk. Most studies have not found an increased chance of birth defects with the use of erythromycin. There are a few studies that have suggested that using erythromycin in the first trimester might be associated with a small increased chance of heart defects and pyloric stenosis (a narrowing of the opening from the stomach to the small intestines). These results were not confirmed in other studies. Based on current studies, including a study that combined and analyzed the data from all the smaller studies, it is considered unlikely that using erythromycin significantly increases the chance for birth defects, such as heart defects or pyloric stenosis.
Does taking erythromycin in pregnancy increase the chance of other pregnancy-related problems?
It is not known if erythromycin can cause other pregnancy-related problems, such as preterm delivery (birth before week 37) or low birth weight (weighing less than 5 pounds, 8 ounces [2500 grams] at birth). Most studies have not shown an increased chance for other pregnancy-related problems when erythromycin is used later in pregnancy. Depending on the condition being treated, use of erythromycin might improve pregnancy outcomes such as gestational age at delivery and birth weight.
Does taking erythromycin in pregnancy affect future behavior or learning for the child?
It is not known if erythromycin increases the chance for behavior or learning issues for the child. One study followed children up to age 11 years who were exposed to erythromycin during pregnancy. The study reported that being exposed to erythromycin during pregnancy did not make the children more likely to need special assistance in school.
If a man takes erythromycin, could it affect fertility or increase the chance of birth defects?
Studies have not been done to see if erythromycin could affect a man’s fertility (ability to get a woman pregnant) or increase the chance of birth defects above the background risk. In general, exposures that men have are unlikely to increase the risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures at https://mothertobaby.org/fact-sheets/paternal-exposures-pregnancy/ .
Quoted from MotherToBaby Fact Sheets — Erythromycin, published November 2023. MotherToBaby states its fact sheets should not take the place of medical care and advice from your healthcare providers.
Breastfeeding is a separate question — what LactMed says about erythromycin
This is general reference information, not medical advice. Whether to take any medication in pregnancy is a decision for you and your prescriber; do not start or stop a drug on your own, because an untreated condition can also carry risk.