Association between asymptomatic bacteriuria in pregnancy and adverse pregnancy- and births outcomes. A systematic review.

Background: Existing guidelines for screening and treatment of asymptomatic bacteriuria (ASB) in pregnancy are based on studies completed more than 30 years ago. This evidence is characterized by a lack of consensus on the association between ASB and adverse pregnancy- and birth outcomes.

Aim: This systematic review aimed to investigate the association between untreated/treated ASB (≥10 colony-forming units (cfu) of the same bacteria per ml urine in two consecutive voided cultures without any symptoms) and pregnancy outcomes (pyelonephritis, chorioamnionitis, prelabour rupture of membranes (PROM)), and birth outcomes (preterm birth (PTB), low birth weight (LBW) and small for gestational age (SGA)).