In every pregnancy, a woman starts out with a 3-5% chance of having a baby with a birth defect. This is called her background risk. This sheet talks about whether exposure to Amoxicillin/Clavulanate may increase the risk for birth defects over that background risk. This information should not take the place of medical care and advice from your health care provider.

What is amoxicillin/clavulanate (amox/clav)?

This combination medication is an antibiotic used to treat a variety of bacterial infections. It is a combination of amoxicillin, a penicillin-like antibiotic, and clavulanate, a drug that increases the effectiveness of amoxicillin. Brand names include Amoclav®, Augmentin XR® and Clavamox®.

Is there an increased risk for miscarriage if I take amoxicillin/clavulanate during the first trimester?

When taken in the recommended doses, amox/clav is unlikely to increase the chance for miscarriage.

Is there an increased chance for birth defects or other pregnancy problems if I take amox/clav during the first trimester?

Most studies have not found an increased chance for birth defects when amox/clav is taken during the first trimester; however, there are very few studies available. There are more studies looking at the use of amoxicillin alone during pregnancy. A few studies have shown an increased risk of cleft lip (opening in the lip) with or without cleft palate (opening in the roof of the mouth) when amoxicillin is taken during the first trimester, while other studies have not supported this increased chance. Based on the current information, the overall risk of a cleft is considered to be low if taking amox/clav.

Is there an increased chance for harmful effects for the baby if I take amox/clav in the second or third trimester?

There is limited information regarding the use of amox/clav during the second trimester, but studies so far do not report an increased chance for birth defects or other pregnancy problems.

For use in the third trimester, there is one large study of women who had an increased risk for preterm labor, a condition in which a woman starts the early stages of childbirth before 37 weeks of pregnancy. Also, those who were treated with amox/clav were found to have a small increased chance for a serious bacterial infection known as necrotizing enterocolitis (NEC) in their newborns. This is a condition that can injure a baby’s intestines. However, a follow-up to this report has found some studies that confirm this chance and others that do not. Overall, the chance that the use of amox/clav increases the risk of NEC is unlikely. However, because of this concern, it has been recommended that amox/clav not be used in women who are at risk for preterm delivery.

Can I take amox/clav if I am breastfeeding?

Yes. Amox/clav enters the breastmilk, however, based on a small number of studies; it has not been shown to cause to cause problems for baby. A study of 67 mothers taking this product found that there were no serious adverse effects in the breastfeeding infants. While some babies had a possible allergic reaction, such as rash, diarrhea, irritability and constipation, the reactions did not last long. If you think your baby has developed a side effect from medicine that might be in your milk, talk to your pediatrician. Also, be sure to talk to your health care provider about all your breastfeeding questions.

What if the father of the baby takes amox/clav?

There are no studies looking at possible risks to a pregnancy when the father takes amox/clav. In general, exposures that fathers have are unlikely to increase risks to a pregnancy. For more information, please see the MotherToBaby fact sheet Paternal Exposures and Pregnancy at

References Available Upon Request