Antibiotics used to treat urinary tract infections in early pregnancy may affect the risk of congenital malformations in babies. A study compared different antibiotics and found that nitrofurantoin and fluoroquinolones had similar risks of malformations as β-lactams, while TMP-SMX had a higher risk. TMP-SMX was linked to increased risks of severe cardiac malformations, other cardiac malformations, and cleft lip and palate compared to β-lactams. Overall, the risk of other types of malformations did not differ significantly between the antibiotics.