Asymptomatic Bacteriuria in Pregnant Women: Frequency, Antimicrobial Susceptibility Profile, Causative Microorganisms and Risk Factors

Introduction: Asymptomatic bacteriuria (ASB) is defined as the presence of bacteria in the urine without significant symptoms of urinary tract infections. ASB occurs during pregnancy and is associated with negative maternal and perinatal outcomes when not treated during pregnancy. The aim of this study was to determine the frequency of ASB, related to risk factors, microorganisms causing bacteriuria and antibiotic susceptibility in pregnant women who presented to the gynecology and obstetrics clinic in our region. Materials and Methods: All pregnant women aged 18 years and over who were admitted to the gynecology and obstetrics clinics of our university hospital between January 1, 2017 and January 1, 2019 were included. Demographic characteristics, clinical risk factors, laboratory findings, and clinical records of the patients were obtained. Urine was collected aseptically. Obtained samples were cultured by routine macroscopy, microscopy examination and appropriate media. Microbial isolates were detected by conventional methods. Kirby Bauer disc diffusion method was used to determine the antimicrobial susceptibility of all bacterial isolates. Data were analyzed with SPSS version 24 software and in all cases, p values less than 0.05 were considered statistically significant. Results: A total of 410 pregnant women were included into the study. Thirty-two patients with ASB were included in the case group and the remaining 378 patients without ASB were included in the control group. Mean age was 30.29 +/- 5.61 years (18-45 years). The prevalence of asymptomatic bacteriuria was 7.8%. There was a statistically significant difference between the parity and ASB. According to the result of statistical analysis, the risk of having ASB in pregnant women who have already given two births has proved a 0.056 fold increase compared with the women who have given only one birth and a 0.045 fold increase for the pregnant women who have given three births compared with the pregnant women who have given two births (Parity; 1; OR: 0.184; 95% CI: (0.023-0.957), 2; OR: 0.056; 95% CI: (0.006-0.580), 3; OR: 0.045 95% CI: (0.002 p<.005). The most common microorganisms were Escherichia coli (59.4%) followed by Enterobacter aerogenes (15.7%) and Staphylococcus aureus (9.4%). The isolates showed susceptibility to commonly used antimicrobials such as nitrofurantoin (93.75%), amikadn (93.75%), tetracycline (93.10%) and trimethoprim-sulfamethoxazole (87.5%). Conclusion: The prevalence of ASB is significantly higher in pregnant women. It is important to screen and treat the disease during pregnancy because it causes a clinical picture that poses a risk for miscarriage and preterm birth. Screening and treatment of pregnant women in terms of ASB will also prevent pregnancy complications and associated adverse birth outcomes. Antibiotic susceptibility test results should be considered in the treatment of pregnant women.