Urinary tract infections (UTIs) during pregnancy

What is a urinary tract infection?

A urinary tract infection (UTI) is an infection of theurinary system. It can occur in different parts of the urinary tract, including the bladder (cystitis) and kidneys (pyelonephritis). The bacteria usually come from the gut (digestive system) where they don’t cause problems, and move to the urinary tract.

Sometimes bacteria is found in the urinary tract, but you don’t have any symptoms of an infection. This is known as asymptomatic bacteriuria. Your doctor or midwife will test for this in your first trimester of pregnancy by asking you to provide a urine sample. If you have bacteria in your urine, even if you don’t have symptoms, your doctor will prescribe treatment, to prevent problems for you or your baby.

UTIs can affect you whether you are pregnant or not. If you’re pregnant, you have up to a 1 in 10 chance of having a UTI. It is the most common infection in pregnancy. If you have a UTI while you’re pregnant, you are also more likely to develop other, more harmful, infections.

What are the symptoms of UTIs during pregnancy?

Common symptoms of a UTI during pregnancy are similar to those that you might experience at any other time, and include:

• pain or a burning sensation when you pass urine
• feeling the urge to urinate more often than usual
• urinating before you reach the toilet (‘leaking’ or incontinence)
• feeling like your bladder is full, even after you have urinated
• urine that looks cloudy, bloody or is very smelly
• pain in the lower abdomen or above the pubic bone
• fever

If the infection has moved to the kidneys, you may also have a high fever, back pain and vomiting.

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What are the common causes of UTIs?

Your urinary tract is normally free of bacteria. If bacteria enter the tract and multiply, they can cause a UTI. Some reasons that increase your risk of developing an infection include:

• being sexually active more than 3 time a week, which increases the risk of bacteria moving around the genital area and entering the urinary tract
• having problems emptying your bladder completely
• having diabetes, as the sugar in your urine may cause bacteria to multiply

During pregnancy, changes that occur in your body will increase your risk of getting a UTI, including changes to your urine and immune system. As your baby grows, there is also increased pressure on your bladder, which can reduce the flow of your urine and lead to an infection. The tubes that take urine from the kidney to the bladder (ureters) get wider, which makes it easier for bacteria to get to the kidneys.

What are the complications of UTIs during pregnancy?

A bladder infection is more likely to become a kidney infection if you are pregnant than if you are not pregnant. In pregnancy, kidney infections are more severe and may cause problems for both you and your baby.

Having bacteria in your urine (even if you don’t have pain or other symptoms) is associated with a condition called pre-eclampsia. Pre-eclampsia is a serious medical condition in pregnancy that causes high blood pressure and can affect many body organs, including the liver, kidney and brain. If left untreated, it can lead to serious problems for you or your baby, but early treatment prevents these problems.

A kidney infection can cause problems such as severe infection (sepsis), blood pressure problems and kidney damage.

Is there a risk to my baby?

If you have bacteria in your urine, or a kidney infection while you’re pregnant, your baby is at a higher risk of an early birth or being born underweight. This risk doesn’t occur with a bladder infection, so long as it is treated.

The best way to avoid a risk to your baby is to keep all your antenatal appointments with your doctor, midwife or clinic.

How are UTIs diagnosed?

UTIs are diagnosed by taking a urine sample, which is checked in a laboratory under the microscope for bacteria. Your doctor will also ask you about your symptoms and may do a physical examination.

Everyone who is pregnant will be offered a urine test, usually at their first antenatal visit or soon after. You may need to repeat the urine test if you have had UTIs in the past, have symptoms of a UTI, have a sample with an unclear result, or if your doctor thinks you are at high risk of developing a UTI. If you have many UTIs, you may need more tests such as an ultrasound of your kidneys.

How are UTIs treated during pregnancy?

UTIs are treated with antibiotics that are safe in pregnancy. Your doctor will prescribe the right antibiotic, based on your infection and the type of bacteria found in your urine sample. If your doctor is concerned about your UTI, they may start you on one antibiotic straight away, and then change the antibiotic if the bacteria is best treated with a different antibiotic.

If you have had many infections or many samples showing bacteria in your urine, your doctor may prescribe regular antibiotics in your pregnancy to prevent more infections from developing (prophylaxis).

It is also recommended to have a repeat urine test a few weeks after you finish your antibiotic treatment to ensure that the infection has cleared.

Can I prevent UTIs?

You can lower your risk of developing a UTI during pregnancy by:

• drinking plenty of fluids, especially water
• going to pass urine (wee) when you get the urge, and not delaying
• urinating immediately after sex
• wiping from the front to the back after going to the toilet
• showering instead of having a bath
• avoiding douching and sprays or powders in the genital area

When should I see my doctor?

See your midwife or GP if you have any symptoms of a UTI. It’s important not to delay getting antibiotics, as infections develop quickly, and can lead to problems for you and your baby.

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Resources and support

For more information on UTIs, visit the Kidney Health Australia page on UTIs.

Mothersafe has information sheets about urinary tract infection in pregnancy.

Read the Queensland Government’s guide to UTIs for Aboriginal and/or Torres Strait Islander people.