Antimicrobial choice in pregnancy should reflect safety for both the mother and the fetus.

During pregnancy, asymptomatic bacteriuria (ASB) significantly increases the risk of pyelonephritis and subsequent maternal and fetal complications. Treatment of ASB significantly reduces these risks.

Pregnant patients should be screened for ASB at least once early in pregnancy, and, if culture is positive, treated for 3 to 7 days. These patients should be followed with serial cultures throughout pregnancy, and prophylactic antimicrobial therapy should be considered.

Pregnant patients with cystitis should also be treated for 3 to 7 days. These patients should be followed with serial cultures throughout pregnancy, and prophylactic antimicrobial therapy should be considered.

Pregnant patients with pyelonephritis should initially be admitted for intravenous antimicrobial therapy and receive a total of 7 to 14 days of culture-directed treatment. These patients should be followed with serial cultures throughout pregnancy, and prophylactic antimicrobial therapy should be strongly considered.