Ultrasound (US) is the Appropriate Imaging for Pregnant Women with Recurrent UTIs
For a pregnant woman with recurrent UTIs, ultrasound of the kidneys and bladder is the recommended imaging modality (Answer B), as it avoids radiation exposure while effectively screening for anatomical abnormalities such as hydronephrosis and incomplete bladder emptying. 1
Rationale for Ultrasound in Pregnancy
Primary Imaging Choice
- Ultrasound is specifically useful in women with recurrent UTIs, particularly prior to and during pregnancy, to evaluate for hydronephrosis and risk factors for recurrent infection 1
- US serves as an effective initial screening tool for obstructive uropathy and can determine postvoid residual volume to detect incomplete bladder emptying 1
- Hydronephrosis can be demonstrated as an indication of obstruction, though US may not always yield a specific etiology 1
Why Other Options Are Inappropriate
X-ray (Option A):
- Abdominal radiography is generally not a useful diagnostic tool for women with recurrent UTIs, as other imaging modalities have higher sensitivity and specificity 1
- Radiation exposure during pregnancy poses risks to the developing fetus and should be avoided when safer alternatives exist 1
Ureteroscopy (Option C):
- This is an invasive procedure not indicated for routine evaluation of recurrent UTIs in pregnancy 2
- Extensive workup including invasive procedures is not routinely recommended for women with recurrent UTIs without specific risk factors 2
Cystoscopy (Option D):
- While cystoscopy may be considered in complicated UTIs with underlying risk factors, extensive workup including cystoscopy is not routinely recommended for women younger than 40 years with recurrent UTIs and no risk factors 2
- The invasive nature and lack of routine indication make this inappropriate for initial evaluation in pregnancy 1, 2
Management Algorithm for Pregnant Women with Recurrent UTIs
Diagnostic Approach
- Obtain urine culture with each symptomatic episode before initiating treatment to guide antimicrobial therapy 2, 3
- Perform ultrasound imaging to evaluate for structural abnormalities, hydronephrosis, and postvoid residual volumes 1
- All pregnant women should be screened for bacteriuria in the first trimester, with repeat screening for those with recurrent infections 4
Treatment Considerations
- Unlike non-pregnant women, all UTIs during pregnancy—including asymptomatic bacteriuria—require treatment due to high risk of ascending infection and complications 5, 6
- Appropriate antibiotics include nitrofurantoin, fosfomycin trometamol, and third-generation cephalosporins (such as cefixime) based on safety profile in pregnancy 7
- Treatment duration should be at least 3 days with appropriate antimicrobials, with close follow-up as recurrence may occur in up to one-third of patients 4
Prevention Strategy
- Consider prophylactic antibiotics for women with recurrent UTIs during pregnancy, as a daily dose of nitrofurantoin with close surveillance has shown reduction in asymptomatic bacteriuria in compliant patients 3
- Close surveillance includes regular clinic visits and urine cultures throughout pregnancy 3
Critical Pitfalls to Avoid
- Never use radiation-based imaging (X-ray, CT) as first-line in pregnant women when ultrasound can provide adequate diagnostic information 1
- Do not defer treatment of asymptomatic bacteriuria in pregnancy, as this significantly increases risk of pyelonephritis and adverse maternal-fetal outcomes 5, 6, 4
- Avoid performing invasive procedures (cystoscopy, ureteroscopy) without clear indication of complicated infection or anatomical abnormality 1, 2