UTI in Pregnancy

Doses are oral and for adults unless otherwise stated. Visit the Health Products Regulatory Board website or the printed Irish Medicines Formulary for drug SPCs, dosage, contraindications, interactions, or IMF/BNF/BNFC/MIMS. See guidance on dosing in children for quick reference dosage/weight guide.

Letters indicate strength of evidence range from A+ (systematic review) to D (informal opinion). Statins can interact with some antibiotics and increase the risk of rhabdomyolysis. Amiodarone and drugs which prolong the QT interval can interact with many antibiotics. Many antibiotics increase the risk of bleeding with anticoagulants. Please refer to our Drug Interactions Table for further information.

Comments from Expert Advisory Committee

  • Send MSU for culture.
  • Nitrofurantion- should be avoided after 36 weeks due to risk of neonatal haemolysis.
  • Fosfomycin - Recommendation for use in pregnancy remains under review pending further evidence and safety data
  • Refer to local resistance patterns for empiric therapy where available and refer to MSU results. Amoxicillin resistance is common – only use if susceptibility data available.
  • Review empirical treatment with results of MSU culture and susceptibility.


Treatment Dose TX Duration
First line nitrofurantoin 50-100mg QDS 7 days
OR amoxicillin (if known to be susceptible)  500mg TDS 7 days
Second line cephalexin 500mg BD 7 days

Patient Information

The HSE Health A-Z website provides patient information on many hundreds of conditions and treatments.

We recommend patients use the website developed by HSE/ICGP/IPU partnership www.undertheweather.ie for tips on how to get better from common infections without using antibiotics, what you can do for yourself or a loved one and when to seek help.

Reviewed April 2018

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