Answer
**in pregnant women & before urologic procedures** - asx UTI can be harmful in these conditions
Pregnant women
--high risk of pyelonephritis
--high risk of premature & LBW babies
--abx decreases both risks
--so screen early, rx for 3-7d, and re-screen intermittently throughout
Urologic procedures
--when mucosal bleeding likely b/c increased risk of bacteremia
--decreased risk with abx pre-procedure
--discontinue abx post-procedure