Urinary tract infections (UTIs) are one of the most common infections in pregnancy. Most are simple bladder infections that clear quickly with the right antibiotic — but in pregnancy they deserve extra respect, because an untreated infection can travel up to the kidneys and increase the risk of premature labour and a small baby.1 The good news: caught early, UTIs are very treatable. Here is what to watch for.

Why pregnancy makes UTIs more likely

Your urinary system — two kidneys, the bladder, and the tubes connecting them — is working harder than ever in pregnancy, and it changes:

  • Pregnancy hormones relax the urinary tubes, so urine flows more slowly.
  • The growing womb presses on the bladder, which may not empty completely.
  • Urine left sitting in the bladder gives bacteria a chance to grow.

A previous history of UTIs, diabetes, and increased sexual activity can add to the risk.

Symptoms of a bladder infection

See your doctor promptly if you notice:

  • Burning or pain when passing urine
  • Needing to go more often or more urgently than usual (beyond the normal pregnancy pattern)
  • Lower tummy pain or discomfort
  • Cloudy, strong-smelling urine, or blood in the urine

Warning signs of a kidney infection — get help the same day

If bacteria reach the kidneys, the infection becomes more serious and needs urgent treatment, sometimes in hospital. Seek medical care straight away if you have:

  • Fever or shivering episodes (chills)
  • Pain in your back or side (loin pain)
  • Nausea or vomiting
  • Feeling generally very unwell

A kidney infection in pregnancy is treated as an emergency — please do not wait for it to settle on its own.2

Infections without symptoms

Sometimes bacteria are present in the urine without causing any symptoms (called asymptomatic bacteriuria). In pregnancy this can still occasionally progress to a kidney infection, which is why some health systems test all pregnant women's urine routinely — practice varies from setting to setting. What matters most for you: attend your antenatal checks, and if a urine test is advised at any point, do have it done — and complete treatment if bacteria are found.1

How UTIs are diagnosed and treated

Diagnosis is simple: a urine test, usually sent for culture so the laboratory can identify the exact bacteria and which antibiotics will kill them.

Treatment is with a pregnancy-safe antibiotic — commonly cephalexin or nitrofurantoin in our practice — guided by your culture result.2 A few important points:

  • Antibiotic choice depends on your stage of pregnancy. Some antibiotics are avoided at particular times — for example, nitrofurantoin is avoided very close to delivery, and trimethoprim is avoided in early pregnancy — so always let any doctor treating you know that you are pregnant, and take only what is prescribed for you.1
  • Finish the full course, even if you feel better after a day or two — stopping early lets the infection return.
  • Drink plenty of water to help flush the system.
  • If your symptoms have not settled by the end of the course, or they come back, return for a repeat urine test — a routine re-test is not usually needed when symptoms clear completely.

Preventing UTIs in pregnancy

Simple habits genuinely help:

  • Drink plenty of fluids throughout the day.
  • Don't hold on — pass urine when you feel the need, and try to empty your bladder fully.
  • Wipe from front to back, and pass urine after sex.
  • Avoid irritants such as perfumed soaps or bubble baths around the genital area.

The takeaway

UTIs in pregnancy are common, easy to diagnose, and safely treatable — the key is acting early. Know the bladder symptoms, take fever with back pain seriously as an emergency, and keep up your antenatal visits. If anything feels wrong, come and see us at Sugabi Clinic — a simple urine test gives quick answers and keeps both you and your baby safe.

References

  1. National Institute for Health and Care Excellence. Urinary tract infection (lower): antimicrobial prescribing (NG109) [Internet]. London: NICE; 2018 [updated 2025; cited 2026 Jul 21]. Available from: https://www.nice.org.uk/guidance/ng109
  2. NHS. Urinary tract infections (UTIs) [Internet]. London: NHS; [cited 2026 Jul 21]. Available from: https://www.nhs.uk/conditions/urinary-tract-infections-utis/