Which organism is most commonly responsible for uncomplicated UTIs during pregnancy?

During pregnancy, the most commonly responsible organism for uncomplicated urinary tract infections (UTIs) is Escherichia coli (E. coli). This bacterium is a normal component of the intestinal flora but can cause infections when it enters the urinary tract. Several factors contribute to the prevalence of E. coli in UTIs, particularly during pregnancy. These include physiological changes such as hormonal shifts and altered urinary tract function, which can predispose pregnant individuals to infections.

E. coli accounts for approximately 80-90% of uncomplicated UTIs, making it the predominant pathogen. Its ability to adhere to uroepithelial cells, combined with its virulence factors, enhances its role in the development of UTIs. Recognizing E. coli as the leading organism helps in accurate diagnosis and treatment, ensuring effective management of UTIs in pregnant individuals, who may have specific considerations regarding antimicrobial safety and efficacy.