Leukocytes in Urine While Pregnant: Causes & Treatment

Leukocytes in Urine While Pregnant

Medically Reviewed By
Dr. Sanjana Sainani (Gynecologist/Obstetrician)
View more Gynecologist/Obstetrician Our Panel of Experts

Your developing baby will demand a lot from your body, and to ensure that your baby is growing and developing properly, you will have to visit the doctor for regular check-ups. Many tests will be performed during every visit; however, one of the tests you will need to take at every check-up is a urinary test. This test can help detect the level of leukocytes or white blood cells in the urine, which can help the doctor confirm infections, if any, that could need treatment and avoid further medical complications. This article will discuss leukocytes in urine pregnancy, their causes, and the treatment available to balance their level.

What Are Leukocytes in Urine?

Leukocytes are white blood cells that are present in the immune system. They help defend the body from infections and diseases. When they appear in the urine, it primarily indicates infection in the kidneys and the urinary system. A rise in the level of leukocytes in the rest of the body also indicates infection.

The average level of leukocytes that should be present in the urine is between 2 to 5 WBCs/hpf. However, if the level of leukocytes rises and goes above 5 WBCs/hpf, it may be a sign of an infection that must be investigated and treated.

What Causes Leukocytes in Urine During Pregnancy?

The number of white blood cells increases in the urine in pregnant women due to one of the following reasons:

1. Urinary Tract Infection

Urinary Tract Infection or UTI is the most common cause of leucocytes in pregnancy. It occurs due to the physiological changes that pregnancy leads to. Leukocytes are usually present in the urine if you are suffering from UTI. When a woman is pregnant, there is an increase in the bladder volume, but the tone will be reduced due to increased levels of the hormone ( estrogen and progesterone ) along with dilatation of ureters.

It is very difficult in this situation to completely empty the bladder, so the bacteria may never fully leave the system. Instead, it multiplies, causing an infection.

urinary tract infection in women

2. Asymptomatic Bacteriuria

When there are bacteria in the urine, and the patient has no symptoms, it is called asymptomatic bacteriuria.

About 30% of pregnant women may have a bacterial infection in the urinary tract but show no symptoms. These can cause leukocytes to manifest in the urine. If left unchecked in pregnant women, this causes pyelonephritis (kidney infection); therefore, doctors need to perform a routine urine test.

3. Genital Infection

Sexually and non-sexually transmittable infections may lead to white blood cells in a person’s urine. Some of the infections that can cause leukocytes to appear in the urine of pregnant women are Chlamydia, vaginal yeast infection, bacterial vaginitisgonorrhoea and genital herpes.

4. Kidney Infections

Kidney infections, or pyelonephritis, develop when an infection of the urinary tract is left untreated in pregnant women. This serious condition must be treated at the earliest to avoid preterm labour or premature rupture of the membranes. Kidney infections can cause leukocytes to appear in the urine and may cause fever, lower back pain and vomiting.

Pregnant women suffer more from this due to the physiological changes during pregnancy, and as the foetus grows, it puts more pressure on the kidneys, further increasing the chances of infection.

5. Cystitis

This type of urinary tract infection leads to the bladder becoming inflamed and causes the number of white blood cells in the urine to rise. It is caused by a bacterial infection and has symptoms similar to UTI, but there is also lower back pain and discomfort in the pelvic region. If the inflammation is severe, traces of blood are found along with leukocytes in the urine.


6. Pyelonephritis

This is a type of kidney infection that can occur during pregnancy. Pyelonephritis can cause leukocytes to be present in the urine, along with other symptoms such as fever, back pain, and nausea.

7. Acute Appendicitis

Although it is not directly related to the urinary tract, acute appendicitis can cause leukocytes to be present in the urine during pregnancy. This is because the inflammation of the appendix can cause irritation and inflammation of nearby organs, including the bladder and urinary tract. Other symptoms of acute appendicitis include abdominal pain, nausea, and vomiting.

Signs and Symptoms of White Blood Cells in Urine While Pregnant

Most often, the signs and symptoms will vary depending on what is causing the rise in leukocyte levels. Some of the main symptoms of leukocytes in urine during pregnancy are:

  • Burning sensation while urinating
  • Frequent urination
  • Unable to empty the bladder
  • Foul-smelling urine
  • Cloudy looking urine
  • Lower back pain
  • Weakness and fatigue
  • A low fever
  • Nausea and vomiting
  • Flank pain
  • Abnormal vaginal discharge


One of the top causes for an increase in the level of leukocytes is urinary tract infection. Other than the symptoms that a pregnant woman would experience, there are other means of diagnosing the levels of leukocytes in urine. Read on to know about how the diagnosis is carried out.

1. How to Measure the Level of Leukocytes?

A urine routine microscopy along with urine culture and sensitivity should be done to see if any bacteria are present in the urinary system. Pregnant women are allowed an increase in leukocytes by 4 to 5 wbc/hpf, only if all other indicators remain unchanged. An increase above 5wbc/hpf indicates that there is most likely an inflammation somewhere in the urinary system or the kidneys. In addition to these diagnostic tests, pregnant women need regular prenatal check-ups to monitor their overall health and identify any potential complications early on. For example, if left untreated, a urinary tract infection can lead to more severe complications, such as preterm labour, low birth weight, or even sepsis. Therefore, it is crucial to seek medical attention if you experience any symptoms of a UTI, including pain or burning during urination, frequent urination, or blood in the urine. Early detection and treatment of leukocytes in the urine during pregnancy can help ensure a healthy pregnancy outcome for both the mother and the baby.

2. How to Analyse?

During the first trimester, the urine routine and microscopy tests are done every three to four weeks. During the second trimester, it is done every two weeks; by the third trimester, it is done every week. The analysis will require the first urine of the morning to be collected in a jar that has been sterilised to avoid contamination of the sample. Your doctor will also need to know all about your medical history, any medications that you are currently on, and your symptoms to identify the cause.

3. Instrumental Diagnosis

This is usually an ultrasound where the bladder, urinary tract, and kidneys are studied. Any enlargement in the pelvic region will be clearly visible in the scan. Ultrasounds can detect neurogenic bladder, polycystic kidney disease, kidney stones, and obstructive uropathy.

4. Differential Diagnosis

In this, clinical urine analysis is done where any increase of white blood cells can be seen. These analyses are compared with a woman’s general condition and complaints. An anamnesis is available to help identify the cause of the condition. A process called urine culture and sensitivity is carried out to identify the main pathogen and select the right therapy. This process delivers accurate results.

Leukocytes diagnosis

After the analysis is done, the treatment must be started immediately to avoid any pregnancy-related complications. We shall talk a little bit about that in the article here on.

5. Flow Cytometry

This diagnostic method uses laser technology to measure the properties of individual cells in a fluid sample. In the case of urine analysis, flow cytometry can quantify the number of leukocytes present in the sample. This method is highly accurate and can differentiate between different types of white blood cells, allowing for a more specific diagnosis of the underlying condition causing the leukocytes in the urine.

After the analysis, the treatment must be started immediately to avoid pregnancy-related complications. We shall talk a little bit about that in the article here on.

6. Lateral Flow Immunoassay

This is a type of rapid diagnostic test that uses antibodies to detect the presence of leukocytes in a urine sample. The test works by detecting the specific antigens on the surface of white blood cells. This method is fast, easy to use, and provides a result within minutes. It is often used in primary care settings as a first-line test for diagnosing urinary tract infections, but it can also be used to detect other conditions that cause leukocytes to be present in the urine during pregnancy.

Effects and Complications

As mentioned earlier, treatment must commence immediately if you have been found with high levels of leukocytes in urine, and the doctors have determined the cause. If, for example, you have been found to have pyelonephritis, which is a kidney inflammation caused by a bacterial infection, your doctor will prescribe certain antibiotics that should be taken while carefully following the instructions to avoid further complications in pregnancy.

Eclampsia is another condition that may arise due to high levels of leukocytes in urine, and it causes a rise in blood pressure. Careful monitoring of your condition during pregnancy can save your baby’s life by avoiding the development of serious complications.

If the diagnosis suggests cystitis, it may turn serious and result in painful urination. Further development of this can turn into gangrenous cystitis, where the pain will be intense, and there is a complete inability to urinate, putting your bladder and peritonitis at risk of rupturing.

Some infections will leave behind a residue of stone as well in the kidney. It is, therefore, highly important to treat any problem at the earliest to avoid some very unpleasant and dangerous complications. Let’s take a look at some ways to treat leukocytes in the urine.

How to Treat Leukocytes in Urine?

There is no fixed method of balancing or decreasing levels of leukocytes in the urine. The treatment will vary depending on the individual’s leukocyte levels and will be based on the diagnosis. Here are some of them:

1. Natural Disinfectants

If the inflammation is not serious, it can be treated with natural disinfectants and diuretics. Most pregnant women will be advised to drink cranberry juice and lots of water.

The urine will be encouraged out of the body with these, decreasing the chance of developing more serious infections.

2. Antibiotics

If the inflammation is more serious, antibiotics will need to be administered, but you must ensure that the doctor prescribes antibiotics that are safe for your baby as well. Antibiotics can help eliminate the infection and prevent more serious complications during pregnancy.

3. Surgery

If you have an obstruction such as kidney stones that are causing the rise in leukocyte levels, you will most probably need surgery to remove the obstruction. Drink plenty of water to try and get rid of the smaller kidney stones, though passing it naturally is quite painful.

4. Sound-Waves, Chemotherapy, and Radiation

Sound waves can be used to break them up for larger kidney stones.

So, what can you do to prevent Leukocytes in urine during pregnancy? Read on to know more. 


Here are some ways to prevent the rise of leukocytes in the urine:

  • Go for regular urine tests.
  • Drink lots of water to flush out the bacteria and toxins from the body.
  • Urinate often and regularly.
  • Maintain personal hygiene by washing your hands before you use the restroom and keeping your genitals clean after you have relieved yourself.
  • When wiping, wipe from front to back.
  • Empty your bladder completely to reduce the risk of bacterial growth in the urinary tract. To do this, lean forward slightly while urinating and gently rock back and forth to help release any remaining urine.
  • Avoid irritating feminine products, such as bubble baths, sprays, or powders, in the genital area that can irritate the urethra or increase the risk of a urinary tract infection.


Here are some frequently asked questions about the occurrence and rise in the levels of leukocytes in urine:

1. Can Increased White Blood Cells in Urine Indicate Blood Leukemia?

No, increased white blood cells in urine never indicate leukaemia.

2. Can an Elevated Number of WBCs in Urine Lead to STD Infection?

White blood cells in urine can never be the cause of STDs; STDs are caused by chlamydial infections.

3. Can Leukocytes in Urine Cause Foetal Death If Left Untreated?

There are cases where the rise in leukocytes in the urine is associated with late toxicosis and other rather serious inflammatory problems. Pregnant women with these conditions are plagued with fatigue and increased pressure on their bladder. They are also at risk of losing the baby due to the chances of preeclampsia.

If the leukocytes esterase in urine during pregnancy, and the inflammation is detected on time, then there is no risk, but if left untreated, there are high chances of complications during childbirth.

4. Can Having Leukocytes in Urine Dangerous During Pregnancy?

Yes, having leukocytes in urine during pregnancy can be dangerous as it may indicate an underlying urinary tract infection or other conditions that can potentially harm the mother and the baby if left untreated. It is important to seek medical attention and receive prompt treatment to prevent complications such as preterm labour, low birth weight, or sepsis.

One of the most important things to follow during pregnancy is to identify and treat any rise in the levels of leukocytes in the urine. If this is not done, it can negatively impact your health and the life of your unborn child. The abnormal WBC in urine during pregnancy count will often be noticed at the earliest as routine urinary tests are a part of the general check-ups for pregnant women. But, if treatment is not followed regularly and care is not taken, the situation can worsen. So, ensure you don’t miss any prenatal check-ups and follow your doctor’s instructions carefully.


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2. Mårdh. P, Novikova. N, Niklasson. O, et al.; Leukocyte Esterase Activity in Vaginal Fluid of Pregnant and Non-Pregnant Women With Vaginitis/Vaginosis and in Controls; PubMed; https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1852264/

3. Yang. W, Yu. X, Liu. D et el.; High false positive rate of white blood cells in urine samples of pregnant women may be caused by epithelial cells being misclassified by the sysmex UF-1000i urine flow cytometer; PubMed;  https://pubmed.ncbi.nlm.nih.gov/30302910/; October 2018

4. Leukocyte esterase urine test; Mount Sinai; https://www.mountsinai.org/health-library/tests/leukocyte-esterase-urine-test

5. Rahiman. F, Balasubramanian, Shejina, Mohthash Musambil; A Review on Urinary Tract Infection in Pregnancy; International Journal of Pharma Research & Review; https://www.rroij.com/open-access/a-review-on-urinary-tract-infection-in-pregnancy.pdf; February 2015

6. Somerville. JA, MAxted. WC, Pahira. JJ; Urinalysis: A Comprehensive Review; American Family Physician; https://www.aafp.org/pubs/afp/issues/2005/0315/p1153.html; March 2005

Also Read: 

CBC (Complete Blood Count) Test in Pregnancy
Change in Urine Colour while Pregnant
Urine Test and Urine Culture during Pregnancy

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