Screening and treating asymptomatic bacteriuria in pregnancy.

PURPOSE OF REVIEW: Asymptomatic bacteriuria (ASB) in pregnancy, if left undiagnosed and appropriately treated can lead to acute pyelonephritis in mothers and low birth weight in infants. Urine culture is the gold standard for diagnosing ASB. Unfortunately, urine culture is limitedly available. The present review aims at evaluating performance of various screening tests and effectiveness of antibiotic regimens for ASB.

RECENT FINDINGS: Positive dipslide test is very likely to have a definitive diagnosis of ASB, whereas a negative result effectively rules out ASB. Available evidences regarding the performance of urine dipstick are still conflicting, it is currently not appropriate to recommend urine dipstick for screening ASB in pregnancy. Choice of antibiotics should be guided by antimicrobial susceptibility testing whenever possible. Nitrofurantoin seems to be antibiotic of choice for ASB in pregnancy. Seven-day regimen of antibiotics gives a better microbiological cure rate but no difference in important clinical outcomes compared with 1-day regimen.

SUMMARY: Dipslide culture is a promising screening test for ASB. Pregnant women with ASB should be treated with 7-day regimen of antibiotics, although 1-day regimen might be appropriate in some settings. More research is needed for identifying appropriate screening tests for ASB.