OG12.5 | Urinary Tract Infection in Pregnancy — Summary & Reflection

KEY TAKEAWAYS

UTI is the most common bacterial infection in pregnancy; E. coli causes approximately 80% of cases. The three forms — asymptomatic bacteriuria (ASB), acute cystitis, and acute pyelonephritis — are distinguished by symptoms, fever, and loin pain. Pregnancy predisposes to upper UTI through progesterone-induced ureteric hypotonia, uterine compression of ureters (hydroureter, stasis), glucosuria, and relative immunosuppression. ASB (≥100,000 CFU/mL, no symptoms) MUST be treated in pregnancy because 20–40% progress to pyelonephritis if untreated; all pregnant women should have an MSU culture at booking. Safe antibiotics include cefalexin (safe throughout) and nitrofurantoin (safe in first and second trimesters — contraindicated after 36 weeks due to neonatal haemolytic anaemia risk). Fluoroquinolones and tetracyclines are contraindicated. Trimethoprim is avoided in the first trimester (antifolate, neural tube defect risk). Pyelonephritis requires inpatient IV antibiotics (ceftriaxone or ampicillin-gentamicin), hydration, foetal monitoring, and watch for AKI and ARDS. Adverse foetal effects include preterm birth (prostaglandin-mediated), IUGR, and LBW.

REFLECT

Lakshmi from the opening scenario has now completed her 7-day course of cefalexin and her test-of-cure culture is negative. She comes for her 28-week visit — should you send another urine culture? The answer depends on her risk profile: if she had a previous UTI episode, diabetes, or urinary tract anomaly, yes, repeat culture is indicated. Think about what you would tell her about reducing her risk for the rest of her pregnancy — hydration, voiding after intercourse, personal hygiene, and the importance of attending for antenatal visits. Now consider the broader picture: India has a high prevalence of UTI in pregnancy, partly because of inadequate access to clean water, sanitation, and antenatal care. What systemic interventions — beyond clinical management of individual cases — would reduce the burden of UTI-related preterm birth and maternal sepsis at the population level?