Bactrim (sulfamethoxazole/trimethoprim) is a prescription drug that’s used to treat or prevent certain infections. Bactrim may not be safe to take while pregnant or breastfeeding.

It may not be safe to take Bactrim while pregnant. However, your doctor may prescribe the drug during certain times of pregnancy or if there are no other treatment options for your condition.

Some studies suggest that exposure to Bactrim during the first 3 months of pregnancy may be linked to a higher risk of problems with fetal development (commonly known as birth defects). Examples include:

If you become pregnant while taking Bactrim, talk with your doctor right away.

If you have questions about Bactrim’s use during pregnancy, talk with your doctor or pharmacist.

If you’re currently breastfeeding or planning to do so, it’s important to understand the effects that Bactrim could have on you or your child.

Bactrim is known to pass into breast milk. Due to certain risks, your doctor may advise you not to breastfeed while taking Bactrim, especially if your child is younger than 2 months old or has certain medical conditions (such as jaundice).

If you’re breastfeeding or planning to do so, talk with your doctor before starting Bactrim treatment.

Disclaimer: Healthline has made every effort to make certain that all information is factually correct, comprehensive, and up to date. However, this article should not be used as a substitute for the knowledge and expertise of a licensed healthcare professional. You should always consult your doctor or another healthcare professional before taking any medication. The drug information contained herein is subject to change and is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. The absence of warnings or other information for a given drug does not indicate that the drug or drug combination is safe, effective, or appropriate for all patients or all specific uses.