Asymptomatic Bacteriuria and Urinary Tract Infection in Pregnant Women with and without Diabetes Mellitus and Gestational Diabetes Mellitus—A Case-Control Study

Background: Asymptomatic bacteriuria (ASB) and urinary tract infections (UTI) during pregnancy may contribute to adverse pregnancy outcomes. Diabetes mellitus (DM) and gestational diabetes mellitus (GDM) are considered to be important additional risk factor for ASB and UTI during pregnancy. Aims: To investigate differences in prevalence of ASB and incidence of UTI in pregnant women with and without DM and GDM to inform ASB screening and treatment policies. Methods: Data from 214 pregnant women who gave birth during 2010 at the Women’s and Children’s Hospital, Adelaide, Australia where cases were women with a clinical diagnosis of (G)DM and controls were matched on date of birth. ASB was defined as the growth of at least 10e5 colony forming units/ml of one organism or any presence of group B streptococcus (GBS) at the first urine culture collected during pregnancy without complaints of a UTI. A clinical UTI was diagnosed by the treating physician, in combination with a positive urine culture it was defined as culture-confirmed UTI. Results: No significant differences in prevalence of ASB (5.6% and 3.7%; relative risk (RR) 1.50; 95% confidence intervals (CI) 0.44 - 5.17), incidence of clinical UTI (4.7% and 11.2%; RR 0.42; 95% CI 0.15 - 1.14) or culture-confirmed UTI (2.8% and 3.7%; RR 0.75; 95% CI 0.17 - 3.27) between pregnant women with and without (G)DM were present. No association was found between ASB and UTI. GBS was the most common causative organism of ASB in women with and without DM (66.7% and 50.0%). Conclusion: In contrast with earlier research, no significant differences in prevalence of ASB or incidence of UTI was found between pregnant women with and without (G)DM.