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Pyelonephritis: kidney infection in pregnancy

Pyelonephritis is a kidney infection that occurs when a urinary tract infection develops. Find out about symptoms of kidney infections in pregnancy, diagnosis and treatment

Pyelonephritis is an infection which has travelled up the urinary tract and has reached the kidney. This condition should always be treated promptly. 

The symptoms of pyelonephritis usually develop over just a few hours, and they can come on very suddenly.

Symptoms of pyelonephritis (kidney infection)

Symptoms of pyelonephritis may include:

  • pain in the lower side of your back, on either side or both sides
  • fever
  • shivering
  • feeling sick
  • vomiting
  • diarrhoea
  • blood in your urine
  • your urine turning cloudy and smelling unusually bad
  • pain when you pass urine
  • needing to go to the toilet more often than normal.

Pyelonephritis is usually treated with antibiotics to clear the infection when you are pregnant. It may require admission to hospital. 

If you are worried about any of these symptoms, see your midwife or GP or contact NHS Direct: 0845 4647.

Further information

NCT's helpline offers practical and emotional support with all aspects of being pregnant, birth and early parenthood: 0300 330 0700. We also offer antenatal courses  which are a great way to find out more about birth, labour and life with a new baby.

NHS Choices has information on kidney infection