Uncomplicated cystitis in pregnancy

Uncomplicated cystitis in pregnancy is a lower urinary tract infection involving the urinary bladder in a pregnant woman without associated structural or functional abnormalities of the urinary tract, significant comorbidities, or features suggesting upper urinary tract involvement.

Pregnancy increases susceptibility to urinary tract infections due to physiological changes, including ureteric dilatation, reduced ureteric peristalsis, and urinary stasis caused by hormonal effects and mechanical compression from the growing uterus.

Although uncomplicated cystitis is usually limited to the bladder, prompt diagnosis and treatment are important because untreated infection may ascend to the kidneys, causing acute pyelonephritis, which may result in maternal and fetal complications.

Epidemiology

Urinary tract infections are among the most common bacterial infections occurring during pregnancy. Cystitis accounts for a significant proportion of symptomatic UTIs in pregnant women.

The most common causative organisms are similar to those causing UTIs in non-pregnant women and include:

• Escherichia coli (most common)

• Klebsiella pneumoniae

• Proteus species

• Staphylococcus aureus

Pregnancy-related changes increase the likelihood of bacterial growth and ascending infection.

Risk factors

Risk factors for uncomplicated cystitis in pregnancy include:

• Previous history of urinary tract infection

• Sexual activity

• Increased urinary stasis during pregnancy

• Poor fluid intake

• Delayed bladder emptying

• Diabetes mellitus

• Previous asymptomatic bacteriuria

• Reduced immunity associated with pregnancy

Pathophysiology

During pregnancy, increased progesterone levels cause relaxation of smooth muscle in the urinary tract, resulting in reduced ureteric contractions and slower urine flow.

The enlarging uterus may compress the ureters and bladder, contributing to urinary stasis. Stagnant urine provides a favorable environment for bacterial multiplication.

Bacteria, commonly originating from the gastrointestinal tract, ascend through the urethra into the bladder and adhere to the urinary epithelium, causing inflammation and symptoms of cystitis.

Without appropriate treatment, infection may progress upward through the ureters, resulting in pyelonephritis.

Clinical presentation

Uncomplicated cystitis in pregnancy usually presents with lower urinary tract symptoms without systemic features.

Symptoms

Common symptoms include:

• Dysuria (painful urination)

• Increased urinary frequency

• Urinary urgency

• Suprapubic discomfort or pain

• Lower abdominal discomfort

• Occasional haematuria

Symptoms suggestive of complicated infection or upper urinary tract involvement include:

• Fever

• Flank pain

• Chills

• Nausea and vomiting

Clinical signs

Possible findings include:

• Suprapubic tenderness

• Increased urinary frequency

• Signs of urinary discomfort

Features such as fever, flank tenderness, or systemic illness suggest progression to pyelonephritis and require further assessment.

Diagnostic criteria

Diagnosis of uncomplicated cystitis in pregnancy is based on:

• Presence of lower urinary tract symptoms.

• Laboratory evidence supporting urinary infection.

Diagnostic findings include:

• Pyuria.

• Positive leukocyte esterase.

• Positive nitrites.

• Significant bacterial growth on urine culture where available.

Investigations

Urinalysis

Urinalysis may demonstrate:

• Leukocytes

• Positive leukocyte esterase

• Nitrites

• Microscopic haematuria

Urine microscopy

May show:

• Increased white blood cells

• Bacteria

• Urinary sediments suggestive of infection

Urine culture and antimicrobial sensitivity testing

Urine culture is useful to:

• Confirm bacterial infection.

• Identify the causative organism.

• Guide antimicrobial therapy.

Culture is particularly important in pregnancy because of the increased risk of complications and recurrence.

Additional investigations

Further investigations are not routinely required in uncomplicated cases but may be considered if:

• Symptoms persist despite treatment.

• Recurrent infection occurs.

• Complications are suspected.

Management

Management aims to:

1. Eradicate infection.

2. Prevent progression to pyelonephritis.

3. Protect maternal and fetal health.

Treatment includes:

• Appropriate pregnancy-safe antibiotics.

• Adequate hydration.

• Monitoring for clinical response.

Non-pharmacological treatment

Supportive measures include:

• Encourage adequate fluid intake unless contraindicated.

• Encourage regular bladder emptying.

• Avoid delaying urination.

• Maintain good personal and perineal hygiene.

• Avoid factors that increase urinary stasis.

Patients should be advised to return for review if symptoms persist or if fever, flank pain, or systemic symptoms develop.

Pharmacological treatment

Antibiotic therapy

Recommended pharmacological management of uncomplicated cystitis in pregnancy includes:

• Nitrofurantoin (PO) 100 mg every 12 hours for 5 days.

OR

• Amoxicillin + clavulanic acid (FDC) (PO) 625 mg every 12 hours for 7 days.

Treatment should be completed as prescribed to ensure eradication of infection and reduce the risk of recurrence or progression.

Where available, antimicrobial therapy should be adjusted according to urine culture and sensitivity results.

Management according to underlying cause

Recurrent cystitis

Patients with recurrent episodes should be assessed for:

• Persistent infection.

• Antibiotic resistance.

• Structural urinary abnormalities.

Further evaluation and specialist review may be required.

Diabetes mellitus

Pregnant women with diabetes require:

• Optimal glycaemic control.

• Close monitoring due to increased risk of infection complications.

Referral

Referral is required if:

• Symptoms fail to improve after appropriate antibiotic therapy.

• There are features of pyelonephritis:

  • Fever

  • Flank pain

  • Vomiting

• There are features of systemic infection or sepsis.

• Recurrent infections occur.

• Structural urinary abnormalities are suspected.

Complications

Potential complications include:

Maternal complications

• Acute pyelonephritis

• Urosepsis

• Recurrent urinary tract infection

• Acute kidney injury

Pregnancy complications

• Preterm labour

• Premature rupture of membranes

• Low birth weight

• Fetal complications associated with severe maternal infection

Prognosis

Uncomplicated cystitis in pregnancy generally has an excellent prognosis when diagnosed early and treated appropriately.

Most women respond well to antibiotic therapy. Delayed treatment increases the risk of ascending infection and pregnancy-related complications.

Prevention

Preventive measures include:

• Adequate fluid intake.

• Regular bladder emptying.

• Early reporting of urinary symptoms.

• Prompt treatment of urinary infections.

• Screening and treatment of asymptomatic bacteriuria according to guidelines.

• Good control of diabetes mellitus.

• Avoiding unnecessary urinary catheterization.