A urinary tract infection (UTI) occurs when bacteria enter and multiply within the urinary system, which includes the urethra, bladder, ureters, and kidneys. While anyone can develop a UTI, pregnant individuals are more susceptible due to hormonal and physical changes during pregnancy.

Research shows that nearly 18% of pregnant women experience a UTI at some point during their pregnancy. Though typically treatable, untreated infections can cause serious complications for both the mother and baby.

Recognizing the symptoms early and seeking proper treatment is key to preventing kidney infections and pregnancy-related complications.

What Causes UTIs During Pregnancy

UTIs are most often caused by Escherichia coli (E. coli)—a type of bacteria that naturally lives in the intestines and near the anus. When these bacteria enter the urethra, they can travel up the urinary tract and cause infection.

During pregnancy, your body undergoes several changes that make you more vulnerable to UTIs, including:

  • Higher progesterone levels, which relax the urinary tract muscles and slow urine flow.

  • Reduced bladder capacity, causing more frequent urination but leaving urine behind, allowing bacteria to grow.

  • Weakened immune response, making it harder for the body to fight off infection.

  • Backflow of urine toward the kidneys (a condition known as vesicoureteral reflux).

These changes increase the risk of bacteria reaching the bladder or kidneys, especially in the later stages of pregnancy.

Common Symptoms of a UTI During Pregnancy

Some pregnant people may have bacteria in their urine without any symptoms—a condition called asymptomatic bacteriuria. However, when symptoms do appear, they often include:

  • Burning or stinging sensation while urinating

  • Frequent urge to urinate, even when little urine passes

  • Cloudy or strong-smelling urine

  • Lower abdominal pressure or discomfort

  • Pain in the back or sides (possible kidney involvement)

  • Fever, chills, or fatigue

  • Urine that appears reddish or contains blood

Because some pregnancy symptoms—like tiredness and frequent urination—overlap with UTI symptoms, signs such as painful urination, foul odor, or cloudy urine are often the clearest indicators of infection.

Are UTIs Dangerous During Pregnancy?

A simple bladder infection (cystitis) during pregnancy is not usually harmful when treated promptly. However, if ignored, the infection can spread to the kidneys—a condition called pyelonephritis—which can be dangerous for both mother and baby.

Untreated UTIs can lead to:

  • Kidney infections

  • Preeclampsia (high blood pressure during pregnancy)

  • Preterm labor or premature birth

  • Low birth weight

For these reasons, healthcare providers routinely perform urine screenings during the first prenatal visit (between 12–16 weeks) to detect any hidden infections early.

Treatment Options

Antibiotic therapy

UTIs are typically treated with short courses of antibiotics that are safe during pregnancy. Treatment usually lasts 5 to 6 days, depending on the infection type and severity.

Some antibiotics, however, are not recommended during pregnancy—especially in the first trimester—because they may increase the risk of birth defects. These include:

  • Ciprofloxacin

  • Nitrofurantoin (in early pregnancy)

  • Trimethoprim-sulfamethoxazole

Your healthcare provider will prescribe the safest option based on your condition and stage of pregnancy.

Severe or kidney infections

If the infection spreads to your kidneys, you may require hospitalization for IV antibiotics and fluids. In some cases, infections caused by Group B Streptococcus may also require special antibiotic treatment.

Prevention Tips

Preventing a UTI during pregnancy is often easier than treating one. Here are effective steps you can take:

  • Drink 6–8 glasses of water daily.

  • Urinate frequently, every 3–4 hours—don’t hold it in.

  • Wipe front to back after using the bathroom to prevent bacteria transfer.

  • Urinate before and after sex.

  • Avoid tight clothing and change out of wet or sweaty clothes quickly.

  • Wear cotton underwear for better airflow.

  • Avoid douching or using perfumed feminine hygiene products.

  • Take showers instead of long baths.

  • Gently wash the vulva and anal area daily with mild soap and water.

Some studies suggest that cranberry supplements or juice may help prevent UTIs by preventing bacteria from sticking to the bladder wall. However, the evidence is mixed, so talk to your healthcare provider before starting supplements during pregnancy.

When To See a Healthcare Provider

Always contact your healthcare provider if you experience signs of a UTI or kidney infection. Symptoms that require urgent attention include:

  • Fever above 101°F (38°C)

  • Chills or night sweats

  • Severe lower back, groin, or side pain

  • Nausea or vomiting

  • Extreme fatigue or confusion

  • Blood in urine or burning sensation while peeing

Even if you feel fine, your provider may test your urine during pregnancy using:

  • Urinalysis: Checks for white blood cells or nitrites that suggest infection.

  • Urine culture: Identifies the specific bacteria causing the infection.

Early detection helps ensure both you and your baby remain healthy.

A Quick Review

UTIs during pregnancy are common but manageable. Hormonal changes, reduced bladder capacity, and a weaker immune system make pregnant people more prone to infection.

With early diagnosis and proper treatment, UTIs rarely cause complications. However, untreated infections can lead to kidney damage, preterm birth, or low birth weight.

Drink plenty of fluids, practice good hygiene, and talk to your healthcare provider if you notice pain, burning, or cloudy urine. Prompt care is the best protection for both you and your baby.