Urinary Tract and Kidney Infections During Pregnancy
What They Are and Why They Matter
Urinary tract infections (UTIs) are one of the most common health issues during pregnancy. They happen when bacteria—usually E. coli from the bowel—enter the urinary system, which includes the kidneys, ureters, bladder, and urethra.
PIH Health Obstetrics & Gynecology Physician Erica Barrios MD says, “During pregnancy, hormones relax your muscles, and your growing uterus puts extra pressure on your bladder and ureters. This slows down the flow of urine and makes it easier for bacteria to multiply.” Because of these changes, UTIs are more common between weeks 6 and 24 of pregnancy. If left untreated, a simple bladder infection can spread to the kidneys (a condition called pyelonephritis), which can be serious for both you and your baby.
Types of Urinary Infections in Pregnancy
- Asymptomatic bacteriuria: Bacteria are found in your urine, but you have no symptoms. About 2–10% of pregnant women experience this. It’s important to treat it early to prevent kidney infection.
- Cystitis (bladder infection): Causes pain or burning when you pee, an urgent or frequent need to urinate, and cloudy or strong-smelling urine.
- Urethritis: Involves the urethra and can also cause burning or irritation when you urinate.
- Pyelonephritis (kidney infection): A more serious infection that may cause back or side pain, fever, chills, nausea, or vomiting. It often requires hospital care with IV antibiotics.
Common Symptoms to Watch For
- Burning or pain when urinating
- Urge to pee often, even when little comes out
- Cloudy, bloody, or foul-smelling urine
- Lower belly pressure or pain
- Back or side pain
- Fever, chills, or nausea (signs infection may have spread to the kidneys)
If you experience any of these symptoms, contact your healthcare provider right away—don’t try to treat it on your own.
How UTIs Are Diagnosed
Your provider will ask for a urine sample to check for signs of infection (such as white blood cells, red blood cells, or bacteria). “If bacteria are found, a urine culture identifies the exact type so your provider can choose the safest and most effective antibiotic during pregnancy,” says Dr. Barrios.
Treatment and Recovery
Antibiotics are the standard treatment and are chosen carefully to be safe for you and your baby. You’ll usually take them for 3 to 7 days. Symptoms often improve within a few days, but it’s important to finish the full prescription to prevent recurrence or kidney infection. If the infection has spread to your kidneys (pyelonephritis), you may need IV antibiotics and monitoring in the hospital for 48 hours or more.
What to Expect if You Have Pyelonephritis
Pyelonephritis affects 1 to 2% of pregnancies and can lead to serious complications like preterm labor or sepsis if untreated. It’s more likely in women with diabetes, recurrent UTIs, or poor prenatal care. Treatment involves IV antibiotics in the hospital followed by oral antibiotics at home for up to two weeks. Once your urine cultures are clear, most women recover fully with no long-term effects.
How to Prevent UTIs and Kidney Infections
You can’t always prevent UTIs, but healthy daily habits lower your risk:
- Stay hydrated: Drink 6 to 8 glasses of water a day.
- Empty your bladder often: Don’t “hold it.” Pee before and after sex.
- Wipe front to back after using the toilet.
- Wear loose cotton underwear and change daily.
- Avoid harsh soaps, douches, or feminine sprays.
- Limit long baths (no more than twice a day, 30 minutes max).
- Take prenatal vitamins as advised: Vitamin C and zinc may help support urinary health.
Women who have had multiple UTIs may need closer monitoring or preventive antibiotics during pregnancy.
When to Call Your Provider
Seek medical care right away if you have:
- Fever, chills, or nausea
- Back or side pain
- Pain or burning when urinating that doesn’t go away
- Blood in your urine
Prompt treatment can prevent complications and keep you and your baby healthy.
UTIs during pregnancy are common and very treatable. “With regular prenatal visits, early testing, and quick treatment, most infections clear up completely without affecting your baby,” emphasizes Dr. Barrios. If something feels off, trust your instincts and call your healthcare provider. Visit PIHHealth.org/Doctor to find a provider near you.
