Urinary Tract Infection In Pregnancy

Clinical description

Urinary tract infection (UTI) and progression to pyelonephritis is a common complication in pregnancy due to untreated asymptomatic bacteriuria.

UTI is defined as ≥ 100,000 organisms/ml if asymptomatic or >100 orgs/ml with pyuria (>7 WBCs/ml) if symptomatic.

Pyelonephritis in pregnancy can lead to acute respiratory distress syndrome (ARDS) and preterm labour.

Therefore, treating UTI to prevent progression to pyelonephritis is imperative.

Signs and symptoms

History/Exam Dysuria, increased frequency and urgency,retropubic/suprapubic pain, abdominal pain.

Often, in pregnancy there are no symptoms. Therefore, urine dipstick should prompt investigation and treatment.

For acute pyelonephritis: spiking fevers or chills, flank/costo-vertebralangle pain or tenderness, anorexia, nausea and vomiting.

Investigations Urinalysis, urine microscopy (clean-catch, midstream sample) should be collected at least once in the pregnancy, preferably at the first antenatal visit.

Urine culture should also be performed if available. If only a urine dipstick is available for evaluation, presence of nitrates and leukocytes is often indicative of an infection, however, in pregnancy there should be a low threshold for treatment.

Treatment

Acute cystitis or Asymptomatic bacteriuria (infection limited to the bladder)

• Cephalexin 500mg QID for 5 days, Amoxicillin 500 mg PO TID for 5 days, Nitrofurantoin 100mg BID for

5days.

• Check urine culture and sensitivities if available. Adjust antibiotics asindicated, especially if first-line

treatment fails.

• If UTI recurs, then check urine culture and sensitivities. Adjust antibiotics.

Acute pyelonephritis (infection of upper tract, mainly of renal pelvis +/- parenchyma)

• Mostly in 2nd and 3rd trimester.
• Signs and symptoms
• Backache, fever, rigors and renal angle tenderness
• Increased risk of preterm labor
• Management
• Admit
• FBC, creatinine, urea and electrolytes and urine culture
• PO or IV hydration
• Monitor urine output
• Ceftriaxone 1g od continue until afebrile for 24hrs, then give oral amoxicillin for total 14 days
• Check urine culture and sensitivities if available prior to starting antibiotic
• Paracetamol 500 mg tds PO for pain and fever

Prophylaxisto prevent future UTIs: After the 3rd UTI or any incidence of pyelonephritis during the pregnancy, prophylaxis should be instituted.

• Prophylactic antibiotics (i.e. nitrofurantoin 50-100mg OD or cephalexin 250-500mg mg OD).Both

trimethroprim/sulfamethoxazole and nitrofurantoin should be avoided in the 3rd trimester of pregnancy