Optimal timing to screen for asymptomatic bacteriuria during pregnancy: first vs. second trimester

Area of Science:

• Obstetrics and Gynecology
• Infectious Diseases
• Maternal-Fetal Medicine

Background:

• Current guidelines recommend screening for asymptomatic bacteriuria (ASB) in pregnant individuals.
• However, the optimal timing for this screening (first vs. second trimester) remains unclear.
• ASB in pregnancy is associated with adverse maternal and fetal outcomes.

Purpose of the Study:

• To determine the optimal timing for screening asymptomatic bacteriuria during pregnancy.
• To compare the rate of positive urinary cultures in the first versus the second trimester.
• To assess the impact of screening timing on obstetrical outcomes.

Main Methods:

• Retrospective cohort analysis of 2,005 pregnant patients.
• Comparison of ASB screening in the first trimester (n=655) versus the second trimester (n=1,350).
• Analysis of germ identification, treatments, risk factors, and complications including urinary tract infection (UTI) and preterm delivery.

Main Results:

• ASB was detected in 3.54% of cases, with similar rates in both the first (3.50%) and second (3.55%) trimesters.
• Escherichia coli was the most common pathogen.
• No statistical difference was observed in ASB rates or association with adverse obstetrical outcomes (e.g., pyelonephritis, preterm delivery) based on screening timing.

Conclusions:

• The timing of asymptomatic bacteriuria screening during pregnancy (first vs. second trimester) has no significant clinical impact on obstetrical outcomes.
• Current recommendations to screen at least once during pregnancy are supported.
• Further research may explore specific high-risk populations.