Is amoxicillin safe during pregnancy?

What does the evidence say about amoxicillin during pregnancy?

1. Most studies on amoxicillin and the related combination drug amoxicillin-clavulanate haven't found a higher chance of major birth defects when either is used in the first trimester. 1
2. A large Danish population study of amoxicillin use in pregnancy found no higher risk of preterm birth, low birth weight, or major malformations, and average birth weight actually ran slightly higher in exposed babies. 2
3. In a study that followed more than 100,000 pregnancies, first-trimester use of amoxicillin or amoxicillin-clavulanate wasn't tied to a meaningfully higher rate of major birth defects, even at higher doses. 3
4. A 2023 review of the amoxicillin research did flag a possible small link to cleft palate across a handful of studies, which is why providers still weigh the type of infection against any antibiotic option before prescribing. 4
5. The FDA-approved drug label notes that animal studies using doses far above the typical human amount haven't shown harm to the fetus, while also advising it should be used in pregnancy only when clearly needed since large controlled human trials haven't been done. 5

Is amoxicillin safe in each trimester?

• First trimester. Amoxicillin is commonly prescribed in the first trimester when you have a bacterial infection that needs antibiotics, and studies looking at amoxicillin by itself haven't found a higher chance of birth defects. A few studies on the combination drug amoxicillin-clavulanate have flagged a small possible increase in cleft lip and palate, but that signal hasn't shown up for plain amoxicillin. Leaving a bacterial infection unaddressed carries its own risks, so most providers see antibiotics as the safer choice when they're truly needed.
• Second trimester. By the second trimester, amoxicillin is considered one of the safer antibiotic choices if you need something for a UTI, sinus infection, or dental infection. Large population studies haven't linked it to preterm birth or low birth weight. Take the full course your provider prescribes, even once you start feeling better.
• Third trimester. Amoxicillin is still a commonly prescribed option later in pregnancy for infections like UTIs, sinus infections, or dental infections. It hasn't been linked to labor complications or newborn problems at typical prescribed doses. Let your delivery team know about any antibiotics you're taking or recently finished.