[Urinary tract infections in pregnancy: when to treat, how to treat, and what to treat with].

Urinary tract infections (UTI) in pregnant women are a relatively frequent occurrence and the spectrum of these infections ranges from lower urinary tract disease (asymptomatic bacteriuria, acute cystitis) to upper urinary tract disease (acute pyelonephritis). Anatomical and functional changes in the urinary tract in pregnancy result in significantly higher susceptibility to progression of the infection from asymptomatic bacteriuria to the stage of acute pyelonephritis. Untreated asymptomatic bacteriuria in pregnancy leads, in as much as 40%, to the development of acute pyelonephritis with all the subsequent negative effects not only for the woman herself, but particularly for the fetus. Bacteriuria in pregnancy accounts for a significantly higher number of newborns with a low birth weight, low gestational age and higher neonatal mortality rate. Therefore, it is necessary to perform screening for bacteriuria in pregnant women and, when the finding is positive, to treat this bacteriuria. The selection of an appropriate antimicrobial agent to treat urinary tract infection in pregnancy is limited by the safety of a given drug not only for the woman, but particularly for the fetus. The article provides an overview of medications that can be safely used throughout the pregnancy or only in certain stages of pregnancy. The selection of an appropriate antibiotic should always be preceded by the result of urine culture. The article presents the principles and rules for treating asymptomatic bacteriuria, acute cystitis and acute pyelonephritis in pregnant women.