Changes in Urine During Pregnancy: What’s Normal and When to Call Your Doctor

Pregnancy affects nearly every system in the body, including the urinary tract. As hormone levels rise, blood volume expands, and the uterus grows, many pregnant people notice changes in how often they urinate, how their urine looks and smells, and how their bladder feels.

These changes can be normal, but they can also signal a problem that needs medical attention, such as a urinary tract infection (UTI). Understanding what’s expected — and what isn’t — can help you stay healthy.

How Urine Changes Throughout Pregnancy

Pregnancy hormones, increased blood flow to the kidneys, and the growing uterus all influence how often you urinate and how your bladder feels during pregnancy.

“Women with multiple pregnancies or underlying health conditions such as high blood pressure, diabetes, pre-pregnancy kidney issues, sickle cell disease, or especially sensitive bladders might notice more pronounced changes,” says Shivika Trivedi, MD, an assistant professor and obstetrician-gynecologist at UChicago Medicine in Illinois.

These shifts can start early and continue throughout pregnancy.

First Trimester Changes

As early as the first trimester, many women notice they need to urinate more frequently, says Jonathan Schaffir, MD, a clinical professor and an obstetrician-gynecologist at the Ohio State University Wexner Medical Center in Gahanna, Ohio.

“Part of this is due to the increased rate at which blood flows through the kidneys,” he says. “There’s actually more urine being produced.”

The need to pee more often is also due to the expanding size of the uterus, says Dr. Schaffir. “During the first trimester, the uterus is competing for space in the pelvis where the bladder is, so bladder capacity may be diminished,” he says.

It’s a good idea to increase your fluid intake when you’re pregnant to accommodate the increased amount of blood in the bloodstream, says Schaffir. “For women who are drinking more liquids, urine may become more dilute,” he says.

Second Trimester Changes

As the uterus grows upward into the abdomen, pressure on the bladder may temporarily lessen. And while there's still more urine being produced, the rate tends to level off at this point, says Schaffir.

Between that and the uterus's new position above the bladder in the abdomen, there may be some reprieve from frequent bathroom trips, he says.

Third Trimester Changes

You may notice a little urine leakage during your last trimester. Two hormones that rise in pregnancy, relaxin and progesterone, cause the relaxation of muscles, ligaments, and blood vessels, including those in the bladder, says Trivedi.

“That allows more urine to be held in the urinary tract itself and also leads to relaxation of the pelvic floor muscles that can cause leakage of urine with a cough, sneeze, or laugh,” she says.

This relaxation also allows increased fluid to pool in the legs, which then reenters the bloodstream when a pregnant person lies down, leading to increased urine production and increased nighttime urination, says Trivedi.

In the final months of pregnancy, the uterus (now holding a larger fetus) puts a lot of pressure on the bladder, so individuals may have difficulty holding much urine in the bladder, which can mean going to the bathroom more frequently again, says Schaffir.

Urine Color and Odor Changes During Pregnancy

Urine Color Changes

• B-complex or prenatal supplements, which may turn urine bright yellow or orange
• Foods like beets, blackberries, and rhubarb, which can cause pink or red urine
• A urinary tract infection (UTI) or, less commonly, kidney stones, which result in cloudy urine
• Blood in the urine, potentially related to an infection or another condition, turning it red or brown

Cloudy or bloody urine should be checked out by your healthcare provider right away, says Trivedi.

Urine Odor Changes

Pregnancy and an Increased Risk of Urinary Tract Infections

“Pregnant patients may have bacteria in the urine without having symptoms, which predisposes them to developing an infection, especially if the bladder isn’t emptied completely,” says Schaffir.

Sugar (glucose) may spill into the urine more easily in pregnancy via leaky kidneys, providing a way for bacteria to thrive, he says.

“If a woman does develop a UTI in pregnancy, there’s a higher chance that it can spread to the kidneys, because the ureter (the tube connecting the kidney to the bladder) is dilated in pregnancy, and the pregnant uterus may rest against the ureter, causing pressure to build up in the collecting system above it,” says Schaffir.

• A strong urge to urinate
• Burning or pain when urinating
• Cloudy urine with a strong smell
• Blood in the urine
• Incontinence

Pregnancy and Group B Strep Disease

It’s also common for GBS to live in the vagina or rectum without any issues in most healthy adults. But you can pass the bacteria to your baby during childbirth, and because they lack immunity to it, GBS can be harmful to them.

Tips on Preventing Infections

• Drinking plenty of water throughout the day
• Emptying your bladder fully and regularly
• Urinating before and after sexual activity
• Wiping from front to back
• Wearing cotton underwear
• Avoiding tight clothing and bubble baths
• Maintaining good genital hygiene

When to See a Doctor About Urine Changes During Pregnancy

Many urine changes in pregnancy are normal. But certain symptoms require medical attention.

• Pain or burning with urination
• A strong, persistent urge to urinate
• Fever, chills, or lower back pain
• Cloudy, foul-smelling, red, or brown urine
• Difficulty urinating
• Signs of dehydration, such as very dark urine or dizziness
• Persistent vomiting that prevents adequate hydration

Seek immediate care if you experience severe abdominal pain, bleeding with clots, or signs of preterm labor.

The Takeaway

• Urine changes, including frequency, color, and odor, are a normal part of pregnancy as hormones shift and the growing uterus puts extra pressure on the bladder.
• Proper hydration, good bathroom habits, and simple prevention strategies can reduce discomfort and lower your risk for urinary tract infections (UTIs).
• Contact your healthcare provider if you notice burning when urinating, pelvic pain, fever, blood in the urine, or strong-smelling urine, as these symptoms can indicate a UTI or another condition that needs prompt treatment.
• Regular prenatal visits and routine urine testing can identify infections and dehydration early, which is when they can be treated most effectively.