What is the best management approach for a 27-year-old pregnant patient (G2P1), at 30.6 weeks gestational age, with recurrent urinary tract infections (UTIs) and right pelvocaliectasis, who has already completed courses of cephalexin (Cefalexin) and nitrofurantoin?

Management of Recurrent UTIs in Pregnancy with Pelvocaliectasis

This pregnant patient with recurrent UTIs and pelvocaliectasis requires targeted antibiotic therapy based on culture results, along with close monitoring of both urinary tract and pregnancy.

Case Assessment

This 27-year-old G2P1 patient at 30.6 weeks gestation presents with:

• Multiple UTI episodes during pregnancy
• Previous treatment with cephalexin (2 courses) and nitrofurantoin (2 courses)
• Current equivocal urinalysis, requiring catheterized specimen
• Ultrasound showing right pelvocaliectasis without obstruction

Diagnostic Approach

1. Confirm the diagnosis:

   • The catheterized urinalysis is essential as it provides more reliable results than clean-catch specimens 1
   • Await culture results from the catheterized specimen before initiating new antibiotics 1
   • Document positive cultures associated with previous symptomatic episodes to establish the diagnosis of recurrent UTI 1

2. Interpret the pelvocaliectasis finding:

   • Physiologic hydronephrosis is common in pregnancy due to hormonal changes and mechanical compression
   • The absence of obstruction on ultrasound suggests this is likely physiologic rather than pathological 1
   • However, pelvocaliectasis increases the risk of complicated UTIs and pyelonephritis 1

Treatment Recommendations

1. Acute UTI management:

   • If culture confirms UTI, fosfomycin trometamol 3g as a single dose is the preferred first-line treatment due to its safety in pregnancy and convenience 2
   • Alternative options include:
     • Cephalexin 500mg four times daily for 7 days (if susceptible)
     • Nitrofurantoin 100mg twice daily for 5-7 days (avoid near term) 2

2. Prevention strategy:

   • After treating the acute infection, implement prophylactic measures:
     • Post-coital antibiotic prophylaxis with cephalexin 250mg single dose after intercourse 1, 3
     • This approach is highly effective and uses fewer antibiotics than daily prophylaxis 3
     • Continue prophylaxis for the remainder of pregnancy 2

3. Monitoring:

   • Obtain follow-up urine culture 1-2 weeks after completing treatment 2
   • Continue screening for recurrent or persistent bacteriuria throughout pregnancy 2
   • Monitor renal ultrasound to assess pelvocaliectasis progression 1

Non-Antibiotic Measures

1. Behavioral modifications:

   • Increase fluid intake (strong evidence for prevention) 2
   • Urinate before and after sexual activity 2
   • Proper wiping technique (front to back) 2
   • Avoid irritating feminine products 2

2. Antimicrobial stewardship considerations:

   • Avoid treating asymptomatic bacteriuria unless pregnant 2
   • Select antibiotics with minimal impact on vaginal and fecal flora 1
   • Consider local resistance patterns when selecting antibiotics 1

Important Considerations

1. Pregnancy-specific concerns:

   • Asymptomatic bacteriuria must be treated in pregnancy to prevent pyelonephritis and adverse pregnancy outcomes 2
   • Avoid TMP-SMX in the first and third trimesters 2
   • Monitor for signs of pyelonephritis (fever, flank pain), which would require hospitalization and IV antibiotics 2

2. Antibiotic resistance:

   • Low-dose prophylactic cephalexin (250mg) has minimal impact on developing resistant flora 4
   • Cephalexin resistance is less common than with other antibiotics 3, 4

3. Follow-up:

   • Continue monitoring throughout pregnancy with periodic urine cultures
   • Repeat renal ultrasound if symptoms worsen or new signs of obstruction develop
   • Consider urological evaluation postpartum if UTIs persist 1

This approach balances effective treatment of the current infection while implementing strategies to prevent recurrence and protect both maternal and fetal health throughout the remainder of pregnancy.