Obstetric Outcome for Pregnant Women with Asymptomatic Bacteriuria in Hong Kong

Abstract

Objective: To determine the prevalence of asymptomatic bacteriuria (ASB) and its effects on the obstetric outcome in Hong Kong pregnant women.
Methods: This was a 6-month prospective observational study carried out in a local obstetric unit, from December 2011 to June 2012. Singleton pregnant women who attended their first antenatal visit during the first trimester, and without symptoms of urinary tract infection (UTI) were recruited. Midstream urine was collected. ASB was defined as a positive culture of >105 colony forming units per ml (CFU/ml) in the absence of white blood cells on microscopy. Treatment was given as appropriate. Their obstetric outcome was evaluated by statistical analysis using odds ratio, t test, and Chi-square test to determine significance.
Results: The incidence of ASB and UTI was 1.7% and 1.6%, respectively. For ASB, the most commonly isolated bacteria was Escherichia coli (38.1%) followed by Streptococcus agalactiae (19.0%). Compared with the control group, the maternal age was younger in the ASB group, but no differences were found in the other characteristics. There was significantly higher risk of neonatal intensive care unit admission and pre-eclampsia with respective odds ratio of 4.2 and 6.8 in the ASB group, but no significant difference was noted in the other outcomes. There was significantly higher risk of low-birth-weight baby (<1500 g) in the borderline bacterial count (≥104 and <105 CFU/ml) group with an odds ratio of 5.9.
Conclusion: There was a higher risk of adverse obstetric outcome in Hong Kong pregnant women with ASB detected during the first trimester.