Among the infections that can affect women during pregnancy, about 10% are represented by urinary tract infections (UTI), which are the most common type of infection during pregnancy. Depending on the part of the urinary tract they affect, they are known as Cystitis and Asymptomatic Bacteriuria, when they occur in the lower tract, or pyelonephritis when the infection in the lower tract ascends. All clinical types of UTI can lead to serious maternal and fetal complications. Thus, differently to the non-pregnant patient, all UTIs during pregnancy, including those with asymptomatic infection, need treatment. When we identify more than one episode in the same pregnancy, prophylactic treatment is recommended.