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Acute lower urinary tract infection in pregnancy — MSRA MCQ

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ModerateUrinary Tract InfectionsAcute lower urinary tract infection in pregnancyMSRA

A 29-year-old woman who is 9+4 weeks pregnant presents with 24 hours of dysuria, urinary frequency and suprapubic discomfort. She has no fever, rigors, loin pain, vomiting, vaginal symptoms or uterine tenderness. Her observations are normal and she is drinking normally. Her eGFR is 88 mL/minute/1.73 m² and she has no drug allergies. A midstream urine specimen can be obtained before treatment. A culture-confirmed Escherichia coli lower UTI 6 months ago was susceptible to nitrofurantoin and cefalexin, but resistant to amoxicillin and trimethoprim. She has not received antibiotics in the past 3 months. What is the most appropriate immediate management?

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Correct answer: C — Send a midstream urine sample for culture and start nitrofurantoin 100 mg modified-release twice daily for 7 days

This is symptomatic lower UTI in pregnancy: dysuria, frequency and suprapubic discomfort are present, while fever, loin pain and systemic illness are absent, making acute pyelonephritis unlikely. A midstream urine sample should be obtained before treatment and sent for culture, but pregnancy requires immediate antibiotic treatment rather than a back-up prescription. Nitrofurantoin 100 mg modified-release twice daily for 7 days is NICE first-line treatment for lower UTI in pregnant women when eGFR is at least 45 mL/minute/1.73 m². Her renal function is adequate, she is in the first trimester rather than at term, and her previous isolate was nitrofurantoin-susceptible. A 3-day course is appropriate for uncomplicated lower UTI in non-pregnant women, not pregnancy. Cefalexin is a reasonable second-choice agent if nitrofurantoin is unsuitable or there is failure to improve after 48 hours, but there is no such indication here. Amoxicillin should be used only when current culture confirms susceptibility; moreover, her previous isolate was resistant. Back-up prescribing is reserved for selected non-pregnant women with lower UTI.

Reference: NICE NG109: Urinary tract infection (lower): antimicrobial prescribing — recommendations (Published 2018; minor updates May 2025) — https://www.nice.org.uk/guidance/ng109/chapter/recommendations NICE NG109: Urinary tract infection (lower): antimicrobial prescribing — Table 2, antibiotics for pregnant women (Published 2018; minor updates May 2025) — https://www.nice.org.uk/guidance/ng109/chapter/recommendations NICE NG109: Summary of the evidence (2018) — https://www.nice.org.uk/guidance/ng109/chapter/summary-of-the-evidence