Why Urinary Tract Infections Are More Common During Pregnancy—And How to Treat Them

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Our Author:

Kerry R. McGee, MD, FAAP

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Dr. Kerry McGee is a pediatrician and mom who knows very well the importance of recognizing and treating UTIs during pregnancy. She earned her medical degree from the University of Virginia and completed her residency training at Oregon Health and Science University in Portland, Oregon. During her education and training, she was pregnant twice, and she has two healthy daughters.

When she first began her clinical practice, Dr. McGee’s first patient was a young woman with a UTI. She has always taken a special interest in the health concerns of adolescents, and she has diagnosed and treated many, many UTIs since then.

Urinary tract infection, or UTI, is common during pregnancy. A UTI happens when bacteria invade your bladder or kidneys and cause an infection. 

Sometimes, this infection causes noticeable symptoms. Other times, a urine test might show bacteria in the urine even though you have no symptoms. Either way, getting it treated is important, because a UTI that isn’t properly treated can result in big problems for you and your baby.

Why are UTIs common in pregnancy?

Pregnancy itself does not cause UTIs. But it does make a UTI more likely to develop because of:

• Changing hormone levels

• Shifts to your vaginal microbiome

• Physical pressure from your growing uterus, which can trap urine in your bladder and give bacteria a place to grow

UTI symptoms in pregnancy

Symptoms of a UTI during pregnancy are the same as those of a regular UTI. The most common are:

• The need to pee frequently

• The urgent need to pee even when your bladder is empty

• Pain or burning when you pee

• Discomfort if you try to hold your pee

• Abdominal, pelvic, or back pain

Some of these symptoms overlap with normal changes during pregnancy. For example, pregnancy  can cause back pain or  the need to go to the bathroom frequently. Pregnancy shouldn’t cause pain or burning when you pee, though. If you aren’t sure about your symptoms, it’s a good idea to talk to your healthcare provider.

If you get a fever with a UTI, that could mean the infection has progressed beyond your bladder to your kidneys. This condition, called pyelonephritis, is a much more serious infection and can result in long-term problems for you and your baby. Any fever during pregnancy is a sign you should seek medical treatment right away.

UTI testing while pregnant

Testing for a UTI requires a sample of urine. Urine samples are collected routinely during prenatal appointments. If you have UTI symptoms in between appointments, you’ll want to make arrangements to get a urine sample tested right away. You can do this in person, or at home. 

Here are the types of tests that might be used to detect a UTI.

Urine culture

The standard test for a UTI is a urine culture. This is done by monitoring a urine sample for several days and measuring the growth of bacteria. 

Normally, urine is sterile, which means no bacteria should grow. If bacteria do grow, laboratory specialists can do more testing to determine what kind of bacteria they are.

Urinalysis

A urinalysis is a faster urine test. For this test, urine is studied under a microscope and checked for signs of infection. The result of a urinalysis can point to a UTI, but it can’t determine what kind of bacteria are causing it.

Urine spot test

Most providers’ offices also do a dipstick or spot test of urine samples. These rapid tests are helpful because they are done in just a few minutes and can show signs of infection when a UTI is present. The downside of rapid urine tests is that they provide much less information than either a urinalysis or a urine culture.

Remember, urine tests for infection are not the same tests that are done to see if you’re pregnant. Having a UTI does not affect a pregnancy test result — or vice versa.

What UTI treatments are safe during pregnancy?

In almost all cases, UTIs during pregnancy need to be treated with antibiotics. Many antibiotics are safe to use during pregnancy. The particular antibiotic you should take depends on the type of bacteria causing your infection and which trimester of pregnancy you are in.

For a simple UTI, antibiotics can usually be prescribed as tablets and taken by mouth. If the UTI has progressed into a kidney infection (pyelonephritis), antibiotics might need to be taken in the hospital through an IV.

Getting the right treatment for a UTI is important during pregnancy. Expert guidance is needed to determine which antibiotic is best for your infection and your stage of pregnancy. 

Antibiotics that are safe for UTI during pregnancy

Finding the right antibiotic for an infection requires knowing what type of bacteria are causing the problem. That said, antibiotics that are effective against some types of UTI-causing bacteria and aren’t generally considered risky to an unborn baby include:

• Penicillin classes

• Cephalosporin classes

• Quinolone classes

• Erythromycin

Antibiotics that are not safe for UTI during the first trimester

Some common antibiotics used to treat UTIs can be a problem during pregnancy. Both nitrofurantoin (Macrodantin) and trimethoprim/sulfamethoxazole (Bactrim or Septra) have been linked to birth defects if taken during the first trimester, when the baby’s internal organs are in an early stage of development. They can be used safely later in pregnancy, however, and are often the most effective options during this time.

If you develop a UTI while you are pregnant, make sure your provider is aware of your pregnancy. Ask specifically about risks to your baby when you fill any prescription for medication.

Over-the-counter treatments for UTI in pregnancy

Phenazopyridine (Azo, Pyridium, or Uricalm) is an over-the-counter medication that helps ease urinary tract pain during a UTI. You can buy Azo at almost any pharmacy, and it is safe to use for a UTI during pregnancy. 

It’s important to remember, though, that this medication is only used to make you feel better temporarily. Since it isn’t an antibiotic, it does not kill bacteria or cure the infection. But it is safe to use along with an antibiotic during pregnancy.

Preventing UTIs while pregnant

There’s no perfect way to keep from getting a UTI during pregnancy. Even if you do everything right, UTIs can still happen — sometimes repeatedly. That said, here are some things you can do to lower your risk of getting a UTI while you’re pregnant.

Get regular prenatal care

Find a healthcare provider you trust. Follow their instructions throughout your pregnancy. The routine tests that are part of good prenatal care can detect a UTI and other medical conditions early, before they become a problem for you or your baby.

Stay hydrated

Drinking plenty of water is a key step in preventing and recovering from a UTI. Keep urine flowing through your system to help wash out any infection that might be getting started.

Take prenatal vitamins

Protect your baby’s development, and keep your immune system working at its best, by avoiding any vitamin deficiencies.

Drink cranberry juice

The data around cranberry juice and cranberry supplements is mixed. Some large studies show that cranberries can prevent UTIs. Others say there isn’t much effect. 

This may be due to different supplements containing different amounts of proanthocyanidin (PAC), which is thought to be the active ingredient. Either way, drinking cranberry juice won’t hurt, and it will help you stay hydrated, too.

Consider probiotics

Probiotics are “good bacteria” intended to supplement your own microbiome. They can sometimes be useful for preventing UTIs, although they aren’t strong enough to treat a UTI on their own. 

Probiotics can also be helpful to take right after you finish a course of antibiotics, to refresh the good bacteria in your body after the antibiotics have had their effect.

Use preventative antibiotics

Preventative, or prophylactic, antibiotics can be a good idea for people who get UTIs over and over again during pregnancy. If this is you, you might want to talk to your healthcare provider about starting a daily antibiotic to keep bacteria counts low.

Of course, the benefit of a daily preventative antibiotic needs to be weighed against the risks it could carry for you and your baby.

Is it even a UTI?

When you’re pregnant, you might be asked to give a urine sample when you don’t have any signs of infection. If you’re feeling fine, you probably don’t have a UTI. But if there’s bacteria in your urine — and no symptoms — that is known as asymptomatic bacteriuria (ASB).

What’s the difference?

Having a UTI causes bacteria in the urine, but it also makes you feel bad. ASB is invisible. There’s no way to know you have it until it shows up on a urine test.

Some people are more likely than others to have ASB during pregnancy, including:

• People who have been pregnant before

• People who have had ASB before

• People with sickle cell disease

• People who are experiencing financial difficulties

Treating bacteriuria during pregnancy

In people who aren’t pregnant, finding bacteria in the urine isn’t a big deal. During pregnancy, though, ASB is taken seriously. Usually, any bacteriuria during pregnancy is treated with antibiotics.

The importance of treating group B Strep

Many different types of bacteria can cause a UTI or ASB, but group B Strep (GBS) is linked to unique problems during pregnancy. 

GBS normally lives in the digestive tract and vagina. Most of the time it doesn’t cause any symptoms — so many people don’t know they have it. During pregnancy, though, GBS can cause:

• Chorioamnionitis (infection of the fluid and membranes around a developing baby)

• Sepsis

• Pneumonia

• Stillbirth

Urine tests may detect GBS during pregnancy. Proper treatment for GBS can prevent serious problems for the pregnant person and their newborn baby.

UTI risks to the parent

A UTI during pregnancy is more than just uncomfortable: It’s a situation that can go from bad to worse if not properly treated. Some of the serious conditions that can affect someone who’s pregnant if a UTI is not properly treated include:

• Pyelonephritis: As mentioned, if a UTI is allowed to grow beyond the bladder to the kidneys, it is called pyelonephritis. This complication is more likely to happen during pregnancy than at other times because of pressure on the bladder from the growing baby.

• Chorioamnionitis: Chorioamnionitis is an infection inside the uterus. It can happen when bacteria reach the amniotic fluid or the membranes that surround a developing baby, and is more likely to occur when there is GBS bacteria in the urine.

• Preeclampsia: This dangerous condition can occur during the second half of pregnancy and often begins with high blood pressure and protein in the urine. There is a strong link between UTI during pregnancy and preeclampsia.

Can a UTI during pregnancy harm the baby?

A mild UTI usually won’t harm your baby. But a UTI that isn’t treated properly with antibiotics can progress into a more severe infection — and this could result in problems for your baby, including:

• Preterm birth: Babies born before 37 weeks’ gestation are at higher risk for infection and other problems than full-term babies. 

• Low birthweight:  Babies that are born very small are at risk for a variety of health problems during infancy and later in life.

• Infection: Bacteria from the pregnant parent’s urinary tract can sometimes cause an infection in the baby after birth. 

Why trust our experts?

Written by:

Kerry R. McGee, MD, FAAP

Kerry McGee, MD, FAAP, has over a decade of experience caring for babies, children, and teenagers as a primary care pediatrician. She has a special interest in adolescent health, particularly in adolescent mental health.

Reviewed by:

Sophie Vergnaud, MD

Sophie Vergnaud, MD, is the Senior Medical Director for GoodRx Health. An experienced and dedicated pulmonologist and hospitalist, she spent a decade practicing and teaching clinical medicine at academic hospitals throughout London before transitioning to a career in health education and health technology.

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