Untreated Asymptomatic bacteriuria at term increases adverse outcomes in both mothers and newborns: Study
Asymptomatic bacteriuria (ASB) is defined as the presence of ≥100,000 colony-forming units (CFU)/mL of bacteria in a clean-catch urine specimen, in the absence of symptoms suggestive of a urinary tract infection (UTI). ASB is a common occurrence during pregnancy. Several studies have established a link between ASB, pyelonephritis, and an increased risk of preterm birth (PTB). As a result, routine screening and treatment of ASB during pregnancy has been widely recommended.
To screen term pregnant women for ASB, isolate bacterial strains, and ensure timely antibiotic treatment to reduce maternal and neonatal complications such as cystitis, pyelonephritis, and adverse neonatal outcomes, a prospective observational cohort study involved 258 pregnant women meeting inclusion criteria. Urine samples were cultured on CLED agar, incubated at 37°C for 48 hours, and analyzed for bacterial isolates and antibiotic sensitivity. Participants were divided into Group A (culture positive) and Group B (culture negative). Data regarding maternal and neonatal outcomes were collected.
Among the 258 women, 51 (19.8%) were culture positive. Escherichia coli was the most common isolate, followed by Klebsiella spp., CoNS, Staphylococcus aureus, Acinetobacter, and Pseudomonas spp. Antibiotic susceptibility varied among strains. Several maternal factors (e.g., hospitalization period, intrapartum/postpartum fever, antibiotic use) and neonatal outcomes (e.g., conjunctivitis, pneumonitis, NICU admission) showed significant differences between groups.
This study uniquely highlights the impact of asymptomatic bacteriuria (ASB) diagnosed at term pregnancy. The findings demonstrate that untreated ASB was not associated with significant maternal infectious complications during labor, delivery, or the puerperium. However, ASB was linked to adverse neonatal outcomes such as preterm births, low birth weight, and an increased incidence of NICU admissions. While the sample size of culture-positive women was a limitation, the study emphasizes the importance of routine urine culture screening at labor admission. Early detection and appropriate management of ASB can contribute to improved neonatal outcomes. Future larger randomized controlled trials are warranted to better define treatment strategies and strengthen clinical guidelines for ASB management at term pregnancy.
Source: Goyal et al. / Indian Journal of Obstetrics and Gynecology Research 2026;13(1):38–43
