UTI (urinary tract infection) during pregnancy

pregnant woman sitting on couch drinking water
Photo credit: Nathan Haniger for BabyCenter

What's a UTI?

UTIs are urinary tract infections. They're generally caused by bacteria from your skin, vagina, or rectum that enter your urethra and travel upstream. You can have a UTI in any part of your urinary tract, which starts at the kidneys, where urine is made; continues through tubes called ureters down to the bladder, where urine accumulates until you pee; and ends with the urethra, a short tube that carries the urine outside your body.

Here are the most common types of UTIs:

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  • Cystitis, or bladder infection - This happens when bacteria stop in your bladder and multiply there, causing inflammation and triggering those familiar symptoms. Cystitis is the most common type of UTI.
  • Kidney infection - Bacteria may also travel from your bladder up through the ureters to infect one or both kidneys. A kidney infection (also called pyelonephritis) is one of the most common serious medical complications of pregnancy. The infection can spread to your bloodstream and become life-threatening for you.

    A kidney infection may also have serious consequences for your baby. It increases your risk of preterm labor and having a low-birth-weight baby, and it has been linked to an increased risk of fetal or newborn mortality.
  • Asymptomatic bacteriuria - It's possible to have bacteria in your urinary tract and have no symptoms. This is known as asymptomatic bacteriuria. When you're not pregnant, this condition generally doesn't cause problems and often clears on its own.

    During pregnancy, however, asymptomatic bacteriuria that's left untreated significantly increases your risk of getting a kidney infection and is associated with preterm labor and low birth weight. This is one reason your urine is routinely tested during pregnancy.

illustration showing urinary infections in a pregnant woman

Jonathan Dimes for BabyCenter

Why it's common to have a UTI in pregnancy

Pregnancy increases your risk of all three types of urinary tract infection mentioned above.

Here's why: Higher levels of the hormone progesterone decrease the muscle tone of the ureters (the tubes between the kidneys and the bladder), slowing the flow of urine. Plus, as your uterus enlarges it may compress the ureters, making it that much more difficult for urine to flow through them as quickly and as freely as usual.

Your bladder also loses tone during pregnancy. It becomes more difficult to completely empty your bladder, and your bladder becomes more prone to reflux, a condition where some urine flows back up the ureters toward the kidneys.

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The upshot of these changes is that it takes longer for urine to pass through your urinary tract, giving bacteria more time to multiply and take hold before being flushed out, and it also becomes easier for the bacteria to travel up to your kidneys.

What's more, during pregnancy your urine becomes less acidic and more likely to contain glucose, both of which boost the potential for bacterial growth.

UTI symptoms

Symptoms of a UTI vary from woman to woman. For a bladder infection, they include:

  • Pain, discomfort, or burning when urinating and possibly during sex
  • Pelvic discomfort or lower abdominal pain (often just above the pubic bone)
  • A frequent or uncontrollable urge to pee, even when there's very little urine in the bladder
  • Urine that's foul smelling or looks cloudy. (If you see blood in your urine call your doctor or midwife as soon as possible because it may be a sign of other problems.)

Since a frequent urge to pee is common during pregnancy, it may be hard to know for sure whether you have a UTI, especially if your symptoms are mild. If you think you might have an infection, be sure to call your healthcare provider so your urine can be tested.

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Symptoms of a possible kidney infection often come on abruptly and commonly include:

  • Fever
  • Chills
  • Pain in your lower back or side just under your ribs, on one or both sides, and possibly in your abdomen
  • Nausea and vomiting

You may also notice blood or pus in your urine and may have some common UTI symptoms as well. If you have any signs pointing to a possible kidney infection, get medical attention immediately.

UTI during pregnancy with no symptoms

Asymptomatic bacteriuria is associated with preterm birth and low birth weight. And if the bacteriuria isn't treated, your chance of developing a kidney infection may be as high as 35 percent. However, with adequate treatment your risk goes down dramatically.

To find out whether there's bacteria in your urinary tract, your practitioner will collect urine at your first prenatal visit and send it to a lab for testing, whether you have symptoms or not. If this initial urine culture is negative, your chances of developing a UTI later in pregnancy are small.

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If the culture is positive, you'll be treated with oral antibiotics that are safe to take during pregnancy. Taking the full course of antibiotics, usually for a week, should clear the infection.

After treatment, you'll be tested again to make sure the infection is gone. (If it's not, you'll be retreated using a different antibiotic.) Repeat urine cultures should be done regularly throughout your pregnancy to make sure you don't have another infection. If the bacteriuria recurs, you'll be treated again and likely be put on a continuous low dose of antibiotics for the remainder of your pregnancy to prevent another recurrence.

UTI treatment

If you develop a UTI during your pregnancy, you'll be given oral antibiotics. The antibiotics will probably relieve your symptoms within a few days, but it's important to complete the entire course that your caregiver prescribed in order to get rid of all of the bacteria in your urinary tract.

You'll be tested after treatment and periodically during your pregnancy (as well as any time symptoms recur) and retreated if necessary. If you keep getting UTIs, you'll need to take a low dose of antibiotics daily for prevention.

If you develop a kidney infection during pregnancy, you'll be hospitalized and started on intravenous fluid and antibiotics, and you and your baby will be carefully monitored. Your caregivers will be assessing a variety of things, including your temperature, blood pressure, pulse, breathing, and ability to make urine; your baby's heart rate; and whether you have any signs of premature labor.

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The length of hospitalization for a kidney infection varies, depending on your situation. If, after an initial 12- to 24-hour assessment, it's clear that you have a mild case, you're responding well to treatment, and preterm labor is not a concern, your caregiver may decide to discharge you from the hospital and switch you to oral antibiotics for the remainder of your treatment.

On the other hand, if you have a severe case, you'll need to remain in the hospital for further treatment and monitoring, and you won't be discharged until 24 to 48 hours after your temperature returns to normal and you no longer have any symptoms.

Once you complete your treatment, you'll be put on a regimen of low-dose antibiotics for the remainder of your pregnancy to help prevent another infection. Without daily suppressive therapy, your risk of getting another kidney infection is very high.

Preventing a UTI

Take these steps to minimize your chances of getting a urinary tract infection:

  • Drink plenty of water. Sip throughout the day to keep your urine clear or pale yellow in color – a sign of proper hydration.
  • Don't ignore the urge to pee. And lean forward to empty your bladder completely when you urinate.
  • After a bowel movement, wipe yourself from front to back to prevent bacteria in the stool from getting near the urethra.
  • Keep your genital area clean with mild soap and water.
  • Clean your genital area and pee before and after sexual intercourse.
  • Drink unsweetened cranberry juice. Studies show that cranberry juice – or taking cranberry pills – may reduce bacteria levels and discourage new bacteria from taking hold in the urinary tract. (Drinking cranberry juice won't cure an existing infection, though, so if you're having symptoms, you still need to see your practitioner right away to get a prescription for antibiotics.)
  • Don't use feminine hygiene products (sprays or powders) and strong soaps that can irritate your urethra and genitals, making them a better breeding ground for bacteria. And don't use douches during pregnancy.
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ACOG. 2020. Urinary tract infections. American College of Obstetricians and Gynecologists. a new window [Accessed August 2021]

ACOG. 2017. Guidelines for perinatal care, eighth edition. American College of Obstetricians and Gynecologists. a new window [Accessed August 2021]

Ailes EC, et al. 2018. Antibiotics Dispensed to Privately Insured Pregnant Women with Urinary Tract Infections — United States, 2014. MMWR Morbidity and Mortality Weekly Report.  67:18–22. a new window [Accessed August 2021]

Bergamin PA, et al. 2017. Non-surgical management of recurrent urinary tract infections in women. Translational Andrology and Urology; 6(Suppl 2): S142-S152. a new window [Accessed August 2021]

Habak PJ and Griggs RP. 2019. Urinary tract infection in pregnancy. National Center for Biotechnology Information. a new window [Accessed August 2021]

IOM. 2005. Dietary reference intakes for water, potassium, sodium, chloride, and sulfate. Food and Nutrition Board, Institute of Medicine, National Academies. a new window [Accessed August 2021]

Matuszkiewicz-Rowinska, J., et al. 2015. Urinary tract infections in pregnancy: Old and new unresolved diagnostic and therapeutic problems. Archives of Medical Science 11(1):66-7. a new window [Accessed August 2021]

Nicolle LE, et al. 2019. Clinical practice guideline for the management of asymptomatic bacteriuria: 2019 update by the Infectious Diseases Society of America. Clinical Infectious Diseases 68(10):83-110. a new window [Accessed August 2021]

Moore A, et al. 2018. Recommendations on screening for asymptomatic bacteriuria in pregnancy. CMAJ 190:E823-30. a new window [Accessed August 2021]

Smaill FM, et al. 2019. Antibiotics for asymptomatic bacteriuria in pregnancy. Cochrane Database of Systematic Reviews. a new window [Accessed August 2021]

UpToDate. 2020. Urinary tract infections and asymptomatic bacteriuria in pregnancy. a new window [Accessed August 2021]

U.S. Preventive Services Task Force. 2019. Screening for asymptomatic bacteriuria in Adults: U.S. Preventive Services Task Force recommendation statement. JAMA 322(12):1188-94. a new window [Accessed August 2021]

Karen Miles
Karen Miles is a writer and an expert on pregnancy and parenting who has contributed to BabyCenter for more than 20 years. She's passionate about bringing up-to-date, useful information to parents so they can make good decisions for their families. Her favorite gig of all is being "Mama Karen" to four grown children and "Nana" to nine grandkids.