Pregnancy: Urinary tract infections

Pregnancy: Urinary tract infections
The frequent and urgent need to urinate is often taken as a normal sign of pregnancy. But what if the cause is a urinary tract infection?

Urinary tract infections are quite common during pregnancy. They are believed to affect up to 13 percent of pregnant women.

What is a urinary tract infection?

A urinary tract infection (UTI) is an infection in the urinary system (i.e., the bladder and kidneys). The microbes responsible are usually bacteria.

There are three types of UTIs:

  • Presence of bacteria in the urine but no symptoms of infection: An estimated 2 to 15 percent of pregnant women suffer from this type of UTI. If left untreated, it can get worse and spread to the kidneys.
  • Bladder infection (cystitis): An estimated 1 to 4 percent of pregnant women develop this type of UTI.
  • Kidney infection (pyelonephritis): This type of UTI affects 1 to 2 percent of pregnant women. In 80 to 90 percent of cases, it occurs during the second or third trimester.

What are the possible complications during pregnancy?

Pregnancy increases the risk of developing a urinary tract infection. Firstly, hormones cause the urethra, the tube through which urine leaves the bladder, to dilate. The uterus also puts pressure on the ureters, the tubes that connect the kidneys to the bladder. As a result, emptying the bladder becomes more difficult, which promotes bacterial growth. Secondly, pregnant women have higher levels of sugar and protein in their urine, especially in late pregnancy. This lowers the acidity of the urine and creates an ideal environment for bacteria to grow.

If left untreated, UTIs can cause complications during pregnancy. For example, they can lead to preterm labour or premature rupture of the membranes. Untreated UTIs are also associated with low-birthweight babies.

What are the symptoms of a UTI?

UTI symptoms include the following:

  • An urgent and more frequent need to urinate
  • Difficulty urinating or passing only a few drops when you still feel the urge to pee
  • Blood in your urine or cloudy, dark urine
  • A burning sensation when you urinate
  • Pain in your lower back or stomach, especially after urinating
  • Odd-smelling urine
  • Fever, chills, or nausea
  • Pressure in the lower abdomen or contractions

Some women experience no symptoms despite the presence of bacteria in their urine. In these cases, the infection is only detected during routine urine testing.

If, at any time during your pregnancy, you think you may have a urinary tract infection, call your health care provider.

How is the infection treated?

UTIs can be treated with antibiotics. Many medications are safe to take during pregnancy. The doctor will determine the appropriate treatment based on the bacteria causing the infection and the woman’s condition.

Following treatment, a urine culture will be taken to confirm that all bacteria have been eliminated. Women sometimes experience recurrent UTIs during pregnancy. When this occurs, the doctor may prescribe antibiotics to be taken as a preventive measure for up to 6 weeks after delivery.

How to prevent UTIs during pregnancy

  • Drink plenty of fluids (at least 8 glasses a day)
  • Wipe from front to back after using the toilet
  • Go to the bathroom as soon as you feel the need to urinate and after having sex
  • Wash your genital area daily
According to some experts, cranberries may help prevent urinary tract infections in women. However, there is not enough evidence for doctors to recommend them to women during pregnancy.

Things to keep in mind

  • Urinary tract infections are common during pregnancy.
  • Untreated UTIs can lead to complications.
  • UTIs are treated with antibiotics.


Naître et grandir

Scientific review: Dr. Chantal Ouellet, physician
Research and copywriting: The Naître et grandir team
Updated: September 2020

 Photo: GettyImages/South_agency


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