Acute Cystitis in Pregnancy

Acute cystitis in pregnancy is infection of the bladder with dysuria, frequency and suprapubic pain, usually from Escherichia coli. It matters because it can progress to pyelonephritis and preterm labour if untreated.

• Risk factors: previous urinary infection, diabetes, sexual activity, poor hygiene, bladder emptying problems.
• Fever and loin pain mean the infection has spread.
• Culture before treatment guides therapy.

Women have burning on urination, frequency, urgency, nocturia, suprapubic pain and sometimes haematuria, without fever or loin pain. Suprapubic tenderness may be present.

• Cloudy or foul-smelling urine.
• No temperature above 38 degrees Celsius.
• Differential diagnosis: vaginitis, urethritis (chlamydia, gonorrhoea), genital herpes, pyelonephritis, interstitial cystitis, normal frequency of pregnancy, bladder stone.
• Complications: pyelonephritis, preterm labour, recurrent infection, haematuria, urinary retention.

The approach is dipstick with culture before treatment.

• Urine dipstick for nitrites and leucocyte esterase; microscopy for pus cells; midstream urine culture and sensitivity.
• Growth of 10^3 colony forming units/mL or more with symptoms confirms infection.
• High vaginal swab and chlamydia test if discharge or negative culture.
• Test of cure culture 1 to 2 weeks after treatment.

The principle is immediate treatment with an antibiotic compatible with pregnancy, changed by culture result.

• Supportive: oral fluids 2 to 3 litres daily; frequent voiding; wipe front to back; avoid scented products.
• Pharmacological: cefalexin 500 mg oral 6-hourly for 7 days; or nitrofurantoin 100 mg modified release oral 12-hourly for 5 days (avoid in the first trimester when alternatives exist, at term and in glucose-6-phosphate dehydrogenase deficiency); or amoxicillin 500 mg oral 8-hourly for 7 days if sensitive; or fosfomycin 3 g oral single dose; paracetamol 1 g oral 6-hourly (maximum 4 g in 24 hours); avoid trimethoprim in the first trimester, tetracyclines and fluoroquinolones; recurrent infection: cefalexin 250 mg oral at night until 6 weeks postpartum.
• Procedures: none.
• Special groups: diabetic women and those with kidney disease have a 10 day course; penicillin allergy uses nitrofurantoin or fosfomycin; group B streptococcus infection is also covered by intrapartum benzylpenicillin 5 g IV then 2.5 g 4-hourly.
• Red flags: fever above 38 degrees Celsius, loin pain, rigors, vomiting, haematuria with clots, contractions.
• Follow-up: culture 1 to 2 weeks after treatment and monthly to delivery; renal ultrasound for recurrent infection; review at 6 weeks postpartum.