How to treat uti in pregnancy

UTI treatments during pregnancy are safe and easy, usually involving a short course (3-7 days) of oral antibiotics. There are two exceptions:

• If you continue to have UTIs after we treat the first one, we may recommend suppressive therapy. You will take a lower dose of antibiotics every day of your pregnancy instead of larger doses for just a few days.
• If you have pyelonephritis (kidney infection), you will need to receive antibiotics through an IV at a hospital.

For most patients, receiving antibiotic treatment is much safer than risking a kidney infection. We will discuss all your health conditions and pregnancy symptoms to determine the best type of antibiotic for you, depending on what will work effectively against the bacteria in your urine.

Not all urine tests are the same

In the third trimester, we’ll likely test your urine for the presence of protein or glucose, which can indicate high blood pressure or gestational diabetes. Around this time, we also test urine for sexually transmittable diseases such as chlamydia and gonorrhea, which can be transferred to your baby.

Neither of these tests will tell us whether you have a UTI. If you’re experiencing UTI symptoms, please tell us so we can perform the appropriate test and begin treatment.

What increases or reduces risk of UTIs during pregnancy?

Women who have or carry the trait for sickle cell disease are at increased risk for UTIs. We test these patients monthly to ensure we detect an infection as soon as possible.

If you have diabetes, you’re also at a higher risk. We might not test you as frequently, but we will consistently look for symptoms. Both conditions make it harder for the body to fight infections.

Just as when you’re not pregnant, you can take specific actions to lower your chances of getting a UTI, such as:

• Wiping front to back in the bathroom
• Urinating before and after sex
• Wearing cotton underwear
• Avoiding tight and wet clothing
• Drinking more water

A urinary tract infection (UTI) is an infection of the urinary system. UTIs are the most common bacterial infection that women develop during pregnancy. They can occur in different parts of the urinary tract, including the bladder (cystitis), urethra (urethritis) or kidneys (pyelonephritis). Sometimes when a UTI develops and bacteria are detected in the urinary tract, you may not have any symptoms of an infection. This is known as asymptomatic bacteriuria.

While anyone can get a UTI, they are much more common in women than men and they are also more likely to occur in the very young and the elderly.

What are the symptoms of UTIs during pregnancy?

Common symptoms of a UTI during pregnancy are similar to those that you might experience at any other time, and include:

• a burning sensation when you pass urine
• feeling the urge to urinate more often than usual
• urinating before you reach the toilet (‘leaking’ or incontinence)
• feeling like your bladder is full, even after you have urinated
• urine that looks cloudy, bloody or is very smelly
• pain above the pubic bone
• fever

Sometimes the first sign of an infection is a faint prickly sensation when you pass urine. If the infection is more advanced and has moved up to the kidneys, you may also experience fever with a particularly high temperature, back pain and vomiting.

What are the common causes of UTIs?

Your urinary tract is normally free of bacteria. If bacteria enter the tract and multiply, they can cause a UTI. There are several factors that increase the risk of developing an infection:

• Infection with common bacteria in your gut, usually from faeces (poo) can contaminate your urinary tract
• Being sexually active increases the risk of bacteria moving around the genital area and entering the urinary tract
• If you have weak pelvic floor muscles your bladder might not empty completely, which can lead to an infection
• Women with diabetes are at increased risk of developing a UTI since the sugar in their urine may cause bacteria to multiply

Are UTIs a risk during pregnancy?

During pregnancy, many changes occur in your body that increase your risk of developing a UTI, including changes to the make-up of your urine and immune system. As your baby grows, there is also an increase in the pressure on your bladder, which can reduce the flow of your urine and lead to an infection.

UTIs can affect women whether they are pregnant or not. However, pregnant women are more likely to develop repeated or more severe infections. Up to 1 in 10 pregnant women will have a UTI but not have any symptoms at all.

Is there a risk to my baby?

Having a UTI during pregnancy can increase your risk of developing high blood pressure, and your baby may be born early and smaller than usual. For this reason, even if you don’t have any symptoms, it is important to treat a UTI as soon as possible.

How are UTIs diagnosed?

UTIs are diagnosed by taking a urine sample which is checked in a laboratory for bacteria. Your doctor may also perform a physical examination if they think you have an infection.

All pregnant women are offered a urine test, usually at their first antenatal visit or soon after. You may need to repeat the urine test if you have a history of UTIs; have symptoms of a UTI; have a contaminated sample or if your doctor thinks you are at high risk of developing a UTI. If you have frequent UTIs, you may also need additional tests such as an ultrasound of your kidneys.

How are UTIs treated during pregnancy?

When you have a UTI, it is important to drink plenty of water to flush out the urinary tract. UTIs are treated with antibiotics that are safe in pregnancy. Your doctor will select the right antibiotic, based on your infection and the type of bacteria found in your urine sample.

Can I prevent UTIs?

You can lower your risk of developing a UTI during pregnancy by:

Some women have also found the following tips helpful:

• urinate immediately after sex
• don’t delay going to the toilet — go as soon as you feel the need
• wipe from the front to the back after going to the toilet
• wear cotton underwear

When should I see my doctor?

See your midwife or doctor if you have any symptoms of a UTI. It’s important not to delay treatment since infections develop quickly, and can affect both you and your baby.

More information

UTIs are very common during pregnancy, and are best treated early. If you notice the symptoms of an infection, seek medical advice from your doctor, midwife or pharmacist.

For more information on UTIs, visit the Kidney Health Australia page on UTIs.

Treatment of bacteriuria and cystitis

Because of the dangers of maternal and fetal complications, acute care should focus on identifying and treating asymptomatic and symptomatic bacteriuria, along with ensuring that an alternate process is not the cause of the symptoms.

Treatment of asymptomatic bacteriuria in pregnant patients is important because of the increased risk of urinary tract infection (UTI) and its associated sequelae, including increased risk of pyelnonephritis, preterm delivery, and low birth weight. [27]  

Behavioral methods

Any discussion of treatment should be prefaced with a discussion of behavioral methods that may be used to ensure good hygiene and reduce bacterial contamination of the urethral meatus, thereby preventing inadequate treatment and recurrent infection. Behavioral methods include the following:

• Avoid baths

• Wipe front-to-back after urinating or defecating

• Wash hands before using the toilet

• Use washcloths to clean the perineum

• Use liquid soap to prevent colonization from bar soap

• Clean the urethral meatus first when bathing

Antibiotic therapy

Oral antibiotics are the treatment of choice for asymptomatic bacteriuria and cystitis. Treatment is most commonly initiated empirically before culture and susceptibility results return. A meta-analysis concluded that although antibiotic treatment is effective in patients with UTIs, the data are insufficient to recommend any specific regimen for treatment of symptomatic UTIs during pregnancy. [28, 29] All of the antibiotics studied were effective in terms of both increasing cure rates of UTI in pregnancy and decreasing the incidence of associated adverse outcomes. Current oral regimens are summarized in Table 1 below.

Table. (Open Table in a new window)

Antibiotics most commonly given as empiric therapy are cephalexin, amoxicillin-clavulanate, or fosfomycin, due to their broader spectrum of coverage than the other antibiotic options. The resistance of Escherichia coli to ampicillin and amoxicillin is 20-40%; accordingly, these agents are no longer considered optimal for treatment of UTIs caused by this organism.

Although 1-, 3-, and 7-day antibiotic courses have been evaluated, 10-14 days of treatment is usually recommended to eradicate the offending bacteria. For example, studies with cephalexin, trimethoprim-sulfamethoxazole, and amoxicillin have indicated that a single dose is as effective as a 3- to 7-day course of therapy, but the cure rate is only 70%. A systematic review that compared single-dose antibiotic treatment with 4- to 7-day treatments concluded that single-dose regimens may be less effective than a short-course regimen, but until more data become available from large trials, pregnant women with asymptomatic bacteriuria should be treated with the standard regimen. [29]

Treatment success depends on eradication of the bacteria rather than on the duration of therapy. A test-for-cure urine culture should show negative findings 1-2 weeks after completion of  therapy. A nonnegative culture result is an indication for a 10- to 14-day course of a different antibiotic.

Recurrent Cystitis

Pregnant women who have three or more episodes of cystitis or bacteruria should be started on daily antibiotic prophylaxis for the remainder of pregnancy. Daily antibiotics should also be considered in pregnant women after one episode of pyelonephritis. Regimens for daily prophylaxis includes nitrofurantion 100 mg nightly, or cephalexin 250-500 mg nightly. A Cochrane review in 2015 noted that the rates of recurrent UTI were no different with a daily dose of nitrofurantoin and close surveillance versus close surveillance alone. More research needs to be done to evaluate this, especially due to the increasing prevalence of antibiotic resistance. 

In patients who are immunosuppressed or have medical conditions that would increase the risk of complications from cystitis, it is reasonable to consider antibiotic prophylaxis after one episode of cystitis.

The standard course of treatment for pyelonephritis consists of hospital admission and intravenous (IV) administration of antibiotics until the patient has been afebrile for 48 hours. The recommended IV antibiotic would be a broad spectrum beta-lactam, such as ceftriaxone. Once culture results with susceptibilities become available and the patient is clinically improved, treatment can be transitioned to an oral antibiotic regimen. For women with a history of extended-spectrum beta-lactamase (ESBL) Enterobacter, carbapenem is recommended. Patients should be discharged with 10-14 days of antibiotic treatment, and then will need daily prophylactic antibiotics for the remainder of pregnancy.  

IV fluids must be administered with caution. Patients with pyelonephritis can become dehydrated because of nausea and vomiting and need IV hydration. However, they are at high risk for the development of pulmonary edema and acute respiratory distress syndrome (ARDS).

Fever should be managed with antipyretics (preferably, acetaminophen) and nausea and vomiting with antiemetics. If fever persists beyond 24 hours, urine and blood cultures should be repeated and a renal ultrasound should be performed.

Preterm labor and delivery are additional risks associated with pyelonephritis. These risks must be evaluated and treated early in the course of admission with tocolysis as necessary per the preterm labor guidelines. If the patient is septic, tocolysis is not recommended.

Inpatient versus outpatient treatment

The prevailing view is that pregnant patients with pyelonephritis require aggressive inpatient hydration and parenteral antibiotics. Pyelonephritis places the patient at risk for spontaneous abortion in early pregnancy and for preterm labor after 24 weeks’ gestation.

However, a randomized, controlled trial of outpatient treatment of pyelonephritis in pregnancy by Millar et al concluded that outpatient therapy is as safe and effective as inpatient care in the treatment of pyelonephritis before 24 weeks’ gestation. [30] Benefits of outpatient care include cost savings and the psychosocial benefits for the patient. Risks include septic shock and respiratory insufficiency. Consideration of outpatient therapy should be limited to selected patients in their second trimester. More study is necessary before a change in the physician’s practice pattern is considered. 

Antibiotic selection should be based on urine culture sensitivities, if known. Often, therapy must be initiated on an empirical basis, before culture results are available. This requires clinical knowledge of the most common organisms and their practice-specific or hospital-specific sensitivities to medications.

Institution-specific drug resistances should also be considered before a treatment antibiotic is chosen. For instance, with E coli infection alone, resistance to ampicillin can be as high as 28-39%. Resistance to trimethoprim-sulfamethoxazole has been described as 31%, and resistance to first-generation cephalosporins may be as high as 9-19%.

Maternal physiologic changes that influence pharmacokinetics include increased glomerular filtration rate (GFR) and renal plasma flow, increased volume of distribution, decreased gastric motility and emptying, and decreased albumin levels. Serum levels of antibiotics are lower in pregnancy because of the gross increase in blood volume and the increased GFR.

Some antibiotics should not be used during pregnancy, because of their effects on the fetus. These include the following:

•  Tetracyclines (adverse effects on fetal teeth and bones)

•  Aminoglycosides (ototoxicity following prolonged fetal exposure)

• Fluoroquinolones; avoid during pregnancy and lactation (toxic to developing cartilage)

• Trimethoprim-sulfamethoxazole; avoid during first and third trimester

Fosfomycin does not achieve therapeutic levels in the kidneys and therefore should not be used in cases of pyelonephritis. 

Nitrofurantoin is safe and effective; however, poor tissue penetration has limited its use in pyelonephritis. Use near delivery can cause hemolytic anemia in the fetus or neonate as a consequence of their immature erythrocyte enzyme systems (glutathione instability). Nitrofurantoin has also been associated with cardiac birth defects when taken in the first trimester. [31]  Given this risk profile, use of nitrofurantoin is best limited to the second trimester. However, nitrofurantoin is also safe and effective for once-daily prophylactic therapy during pregnancy. [32]

Macrolides are not first-line agents for UTI in pregnancy. However, they are well tolerated by mother and fetus

Trimethoprim-sulfamethoxazole is a safe medication to treat UTIs during the second trimester. Trimethoprim is a folic acid antagonist and has been associated with an increased risk of birth defects when taken in the first trimester during organogenesis. [31]  Sulfonamides are avoided at term because they displace the bilirubin from its binding site in the newborn, which give a theoretical risk of kernicterus. 

Surgical care is rarely indicated. Cystoscopy may aid in establishing the diagnosis of urethral or bladder diverticulum, bladder stones, urethral syndrome, lower urinary tract trauma, interstitial cystitis, or bladder cancer.

A retrograde stent or a percutaneous nephrostomy tube should be placed to relieve ureteral colic or decompress an obstructed infected collecting system. More invasive procedures, such as ureteroscopic stone extraction, [33]  are rarely indicated. Extracorporeal shock wave lithotripsy (ESWL) is contraindicated in pregnancy.

In the rare patient for whom invasive surgical therapy is indicated, the operation should be planned for the second trimester. Surgical intervention during the first trimester is associated with increased risk of miscarriage; surgery in the third trimester is associated with increased risk of preterm labor. Urgent surgical intervention in the third trimester should coincide with delivery of the fetus.