Is there a risk to taking antibiotics for a uti while pregnant?

Depends: Certain class of antibiotics, e.g., sulfamethoxazole-trimethoprim (bacrim, septra), Nitrofurantoin (macrodantin), are harmful to pregnant mother and/or to fetus and not recommended especially when pregnancy is close to term.

Depends: Some antibiotics like penicillins, Ampicillin amoxicillin, Clindamycin + Erythromycin are perfectly safe. Tetracyclines should definitely not be used, they can damage a pregnant woman's liver + can discolor the baby's teeth after birth. Macrodantin + Bactrim (sulfamethoxazole and trimethoprim) are probably safe although recent studies have cast suspicion thb t there many be a tiny risk of birth defects. Always check with OB dr. 1st.