Urinary Tract Infection (UTI) in Pregnancy in Primary Care

Publication: 30/09/2010  --
Last review: 27/04/2021  
Next review: 27/04/2024  
Clinical Guideline
ID: 2236 
Approved By:  
Copyright© Leeds Teaching Hospitals NHS Trust 2021  


This Clinical Guideline is intended for use by healthcare professionals within Leeds unless otherwise stated.
For healthcare professionals in other trusts, please ensure that you consult relevant local and national guidance.

Urinary Tract Infection (UTI) in Pregnancy in Primary Care

See NICE visual summary lower UTI NG109

Bacteriuria should be treated in pregnancy regardless of symptoms i.e. symptomatic UTI and asymptomatic bacteriuria.

Immediate antibiotic treatment is to prevent upper UTI, pre-term delivery and low-birth weight babies.

Symptoms of lower UTI

Always send a MSU for culture & sensitivity and start empirical antibiotics immediately (see below). Review when result available, change antibiotic if bacteria resistant to empirically prescribed antibiotic. Send MSU a week after finishing antibiotics as test of cure.
Refer if evidence of treatment failure

Symptoms of Upper UTI

Refer to secondary care

Asymptomatic bacteriuria (AB)

  • Significant levels of bacteria (>10^5 cfu/ml) in urine but NO symptoms of UTI
  • AB is a risk factor for pyelonephritis and premature delivery
  • AB is routinely screened for (MSU) and treated with antibiotics in pregnant women
  • Send MSU at first antenatal visit with the midwife; if significant bacteriuria indicated on result, confirm with a repeat MSU (to differentiate between true bacteriuria and contamination)
  • Start antibiotics guided by culture and sensitivity results if bacteriuria confirmed
  • Send MSU a week after finishing antibiotics as test of cure. 

Empirical Antimicrobial Treatment of lower UTI in pregnant women

Be guided by any previous urine culture results and any previous antibiotics

 Preferred Option

Alternative Option


Nitrofurantoin MR PO 100mg 12-hourly for 7 days (avoid after 38 weeks)

Cefalexin electronic Medicines Compendium information on Cefalexin PO 500mg BD 7 days

Do not use nitrofurantoin at term i.e. during labour and delivery due to risk of neonatal haemolysis.

Nitrofurantoin is CONTRA-INDICATED in patients with CrCl<30mL/min, and should be used with CAUTION in patients with CrCl 30-44mL/min for short courses for bacteria and on benefit vs risk assessment.

Avoid in patients with suspected or known glucose-6-phosphate dehydrogenase (G6PD) deficiency.

Nitrofurantoin is less effective in alkaline urine; patients should not take alkalinizing agents when on nitrofurantoin.

Cefalexin electronic Medicines Compendium information on Cefalexin should not be prescribed if patient has a history of immediate hypersensitivity to penicillin/other beta-lactams but may be used with caution in patients with other, non-severe penicillin sensitivity.

Directed Antimicrobial treatment

Guided by culture and sensitivity results.

Options include amoxicillin 500mg TDS, trimethoprim 200mg BD (do not use in first trimester, in patients with folate deficiency, low dietary folate intake or taking folate antagonists), nitrofurantoin MR 100mg BD, Cefalexin electronic Medicines Compendium information on Cefalexin 500mg BD.

Treatment Duration
A 7 day course is recommended.

SIGN 2012

General Principles for Treating Infections

This summary table is based on the best available evidence, but use professional judgement and involve patients in management decisions.

  1. This summary table should not be used in isolation; it should be supported with patient information about safety netting, back-up antibiotics, self-care, infection severity and usual duration, clinical staff education, and audits. Materials are available on the RCGP TARGET website.
  2. Prescribe an antibiotic only when there is likely to be clear clinical benefit, giving alternative, non-antibiotic self-care advice, where appropriate.
  3. If person is systemically unwell with symptoms or signs of serious illness, or is at high risk of complications: give immediate antibiotic. Always consider possibility of sepsis, and refer to hospital if severe systemic infection
  4. Use a lower threshold for antibiotics in immunocompromised, or in those with multiple morbidities; consider culture/specimens, and seek advice.
  5. In severe infection, or immunocompromised, it is important to initiate antibiotics as soon as possible, particularly if sepsis is suspected. If patient is not at moderate to high risk for sepsis, give information about symptom monitoring, and how to access medical care if they are concerned.
  6. Where an empirical therapy has failed or special circumstances exist, microbiological advice can be obtained from LTHT Microbiology (Mon-Fri 9am-5pm and Sat and Sun 9am-1pm: 07825 906030, 0113 39 23962/28580; Otherwise via LTHT switchboard - ask for the On call Microbiology Registrar)
  7. Limit prescribing over the telephone to exceptional cases.
  8. Use simple, generic antibiotics if possible. Avoid broad spectrum antibiotics (for example coamoxiclav, quinolones and cephalosporins) when narrow spectrum antibiotics remain effective, as they increase the risk of Clostridium difficile, MRSA and resistant UTIs.
  9. Avoid widespread use of topical antibiotics, especially in those agents also available systemically (for example fusidic acid); in most cases, topical use should be limited.
  10. Always check for antibiotic allergies. A dose and duration of treatment for adults is usually suggested, but may need modification for age, weight, renal function, or if immunocompromised. In severe or recurrent cases, consider a larger dose or longer course.
  11. Avoid use of quinolones unless benefits outweigh the risk as new 2018 evidence indicates that they may be rarely associated with long lasting disabling neuro-muscular and skeletal side effects.
  12. Refer to the BNF for further dosing and interaction information (for example the interaction between macrolides and statins), and check for hypersensitivity.

Note: Doses are oral and for adults unless otherwise stated. Please refer to BNF for further information.
Letters indicate strength of evidence:
A+ = systematic review: D = expert opinion


Record: 2236
Clinical condition:

Urinary Tract Infection in pregnancy

Target patient group:
Target professional group(s): Primary Care Doctors
Adapted from:

Management of Infection guidance for primary care for consultation and local adaptation

Evidence base

Grading of guidance recommendations
The strength of each recommendation is qualified by a letter in parenthesis.

Study design


Good recent systematic review and meta-analysis of studies


One or more rigorous studies; randomised controlled trials


One or more prospective studies


One or more retrospective studies


Non-analytic studies, eg case reports or case series


Formal combination of expert opinion


Document history

LHP version 3.0

Related information

Not supplied