Leukocytes In Urine During Pregnancy: Causes And Treatment

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Urinalysis is a part of the routine prenatal tests to diagnose any medical condition during pregnancy, including kidney infections, preeclampsiaⁱA pregnancy disorder characterized by high blood pressure, water retention, and protein content in urine. , and gestational diabetesⁱA condition characterized by elevated blood sugar levels due to hormonal and physical changes in pregnancy.

. It also detects the increase of leukocytes in urine during pregnancy, which may indicate the presence of any infection or inflammation of the genitourinary or urinary tract. You may also need the urinary test to check the functioning of the maternal organs (1) (2).

Read on to know the causes, risk factors, symptoms, diagnosis, treatment management, and preventive measures for leukocytes or white blood cells (WBCs) in urine when pregnant.

What Are Leukocytes In Urine?

Leukocytes or WBCs are a part of your immune system and include granulocytes (neutrophils, eosinophils, and basophils), monocytes, and lymphocytes (T cells and B cells). Together, these WBCs help the body fight infections and other diseases.

In general, measuring the leukocyte count is a part of a complete blood cell count (CBC) test (3). However, if urinary tract infections (UTIs) or inflammation are suspected during routine prenatal testing, your health care provider may suggest a urine test to detect the presence of leukocytes (particularly neutrophils). Normally, urine is sterile, so the normal range of leukocytes in urine is low, i.e., up to 5 WBCs per high power field (WBC/HPF) (4).

According to Dr. Alan Lindemann, obstetrician, who was also a former clinical associate professor at the University of North Dakota, Grand Forks, “Leukocytes are elevated in blood and urine during pregnancy, but the normal depends on where you start. If your non-pregnant WBC is 5000, then a WBC of 10,000 or 11,000 is probably normal for pregnancy, but if you start your pregnancy with a higher WBC, normal for you could rise to 15,000.

“A urine WBC might not signify a bladder infection, but it could forecast trouble. An elevated WBC could represent a Group B strep infection, so a urine culture is needed because a Group B strep bladder infection can cause kidney infection and preterm labor or birth.”

Causes Of Leukocytes In Urine During Pregnancy

During pregnancy, elevated levels of leukocytes in urine may occur due to various infections, including

1. Urinary tract infection: UTIs are already common in women and its probability increases by 8% during pregnancy, and it is mostly caused by Escherichia coli. The decreased ability of the lower urinary tract to resist invading bacteria during pregnancy contributes to the development of UTI during pregnancy.  Subsequently, the leukocyte count in urine increases to fight off this infection (5).
2. Asymptomatic bacteriuria: According to a study by University Hospitals of Geneva, asymptomatic bacteriuria affects 2% to 7% of pregnant women. This UTI causes a bacterial infection without symptoms, causing leukocytes to appear in the urine. Untreated asymptomatic bacteriuria can be life-threatening as it can lead to pyelonephritis (kidney infection) and affect the fetus. Therefore, it is recommended to do repeated urine cultures or urine dipstick leukocyte esterase tests (a faster screening method) during pregnancy to measure the leukocyte level (6).

3. Genital infections: Certain genital infections, including bacterial vaginosisⁱA common vaginal infection caused due to overgrowth of bacteria that are naturally found in the vagina. , vaginitisⁱInflammation of the vagina. , and vaginal yeast infection, are common during pregnancy. They are mainly caused by hormonal changes and can lead to pyuria (causing leukocytes in urine) (6) (7).
4. Pyelonephritis: It may develop when a UTI or asymptomatic bacteriuria is untreated during pregnancy. It is a severe systemic kidney infection that can cause high amounts of leukocytes in the urine and have negative pregnancy outcomes (5) (6) (8).

Quick fact

Most women develop obstetric pyelonephritis symptoms in the second trimester because of urinary stasisⁱAlso known as urine retention, is the blockage of urine flow through the bladder or urethra. . Also, the majority of immunological changes in the urinary tract peak during this phase (8).

5. Cystitis (bladder inflammation): This UTI affects around 1% of all pregnancies. It is differentiated from asymptomatic bacteriuria by symptoms such as dysuria, urine urgency or frequency, and suprapubic pain (pain in the lower abdomen) without evidence of systemic illness. Since it causes elevated WBC levels in the urine, a urinalysis is used to diagnose it in pregnancy (9) (10).
6. Trichomoniasis: Although uncommon in pregnancy, this sexually transmitted infection (STI) may cause excess WBCs in the urine due to inflammation (11) (12).

Symptoms Of White Blood Cells In Urine When Pregnant

The symptoms of WBCs or leukocytes in the urine samples of pregnant women may vary depending on the underlying cause. Some of these symptoms include (13) (14)

• Dysuria (pain or burning while urinating)
• Frequent urination
• Urine urgency
• Suprapubic pain
• Foul-smelling urine
• Flank pain or renal angle (lower back) pain
• Rigor
• Fever (pyrexia)
• Nausea and vomiting

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Diagnosis Of Leukocytes In Urine During Pregnancy

Dr. Lindemann observes, “There are two ways to check for leukocytes in urine during pregnancy: a clean catch urine sample or sterile catheterization. With more vaginal discharge in pregnancy, sterile catheterization is the most accurate test for leukocytes during pregnancy.”

The following diagnostic methods can be used to detect leukocytes in urine (14):

1. Leukocyte esterase urine dipstick test: Increased WBCs or leukocytes in the urine sample of a pregnant woman can be diagnosed using a leukocyte esterase urine dipstick test. The procedure includes (1) (15) (16)

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• Collection of the urine sample: Generally, a clean-catch urine sample is recommended. Your doctor may provide a clean-catch kit with a washing solution and sterile wipes, or you may be asked to collect a small sample of clean, midstream urine in a sterile plastic cup.
• Urine dipstick test: Your health care provider may test the sample right after the urine sample collection. Chemically prepared testing strips of leukocyte esterase with a color-sensitive pad are dipped into your urine sample to screen for indicators such as leukocytes.

Quick fact

Leukocyte esterase test results may be impacted by how urine samples are stored. There is a chance that positive samples could become negative after being stored for 24 hours (19).

• Positive test: If the strip changes color within 30 seconds to two minutes (depending on the brand), it is taken as a positive test, suggesting infection or inflammation in the urinary tract.
• Negative test: If the strips show no color change, your urine sample may not have a significant amount of leukocytes. However, high protein and vitamin C levels in the urine or specimen contamination with vaginal secretions may interfere with the result. In such cases, your doctor may recommend a urine culture if you have other symptoms suggestive of UTI.

2. Microscopic urinalysis: If your leukocyte esterase urine dipstick test is positive, a microscopic examination of the urine and urine culture and sensitivity are performed to determine the WBC level and check for indicators of infection.

The urine sediment of a fresh urine sample is centrifuged at 1,500 to 3,000 rpm for five minutes and resuspended in the remaining liquid for analysis

. A single drop is deposited on a clean glass slide, covered with a coverslip, and viewed under a microscope.

Point to consider

Epithelial cells may be mistaken for WBCs by the Sysmex UF-1000i urine flow cytometerⁱAn automated screening device that analyzes urine for the diagnosis of urinary tract infections (UTIs). . Therefore, pregnant women’s urine samples may occasionally test positive for WBCs (20).

3. Urinary leukocyte cast: They can be used to identify the location of the illness in the genitourinary tract.

Treatment Of Elevated White Blood Cells In Urine During Pregnancy

The treatment options may vary depending on the cause and elevation level of leukocytes in the urine. Some standard treatment methods that may be included in your prenatal care regime to help balance or decrease the levels of leukocytes in urine during pregnancy are

1. Antibiotic therapy: Almost all the conditions causing elevated leukocytes in urine during pregnancy can be managed with appropriate antibiotic treatment. However, certain antibiotics, such as fluoroquinolones, are contraindicated during pregnancy. Hence, consult an obstetrics and gynecology specialist before taking any antibiotics (17).
2. Natural remedies: Consumption of cranberries, garlic, probiotics, parsley, L-arginine supplements, and sufficient water can help treat UTI and other urinary tract infections during pregnancy (18). However, consult a healthcare provider before starting any natural remedies to ensure they are safe for you and your baby.

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Complications Of Elevated White Blood Cells In Urine During Pregnancy

Treatment should be initiated soon after a high level of leukocytes is detected in urine samples to prevent adverse obstetrical outcomes

. Some of the maternal complications include (10)

• Preeclampsia
• Anemia
• Preterm delivery
• Maternal sepsisⁱA fatal illness in mothers defined by organ dysfunction due to an infection during pregnancy, abortion, childbirth, or postpartum.
• Chorioamnionitis (bacterial infection in the membranes surrounding the fetus)

It can also cause the following complications in the fetus and affect fetal development (20):

• Low birth weight
• TachycardiaⁱIncreased heartbeat (more than 100 beats per minute).
• Premature birth

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• Growth restriction
• Stillbirth
• Perinatal mortalityⁱA term used to describe infant deaths between 28 weeks of pregnancy and less than seven days after birth.
• Mental retardation
• Developmental delay

Prevention Of Elevated White Blood Cells In Urine During Pregnancy

Here are some tips that may help prevent elevated leukocytes in the urine and improve maternal health (13) (18):

• Do regular urine tests as suggested by your doctor to prevent recurrent infections
• Drink plenty of water
• Consume cranberry juice and supplements

Image: IStock

• Maintain good hygiene practices, such as wiping from front to back after a bowel movement
• Avoid synthetic and tight-fitting lingerie
• Avoid perfumed genital washing gels

Infographic: Indicators And Underlying Causes Of Urinary Leukocytes During Pregnancy

The presence of increased leukocytes in urine during pregnancy indicates an underlying infection. Identifying early symptoms and the underlying causes are crucial for appropriate management. Let’s look at the infographic below, as it explains various possible symptoms and causes of urinary leukocytes during pregnancy.

Illustration: Momjunction Design Team

Illustration: Leukocytes In Urine During Pregnancy: Causes And Treatment

Image: Dalle E/MomJunction Design Team

Uncover the potential resons behind the presence of high WBCs in urine during pregnancy and when to consult the doctor about it

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Reviewer Expert Author Editor Fact Checker

Dr Esha ChainaniMS

Dr. Esha Chainani is an obstetrician, gynecologist, and laparoscopic surgeon working in Mumbai. She has over four years of experience and specializes in pregnancy care, high-risk pregnancies, fertility, vaginal bleeding, fibroid surgery, fertility surgeries, PCOS, and endometriosis.

Read full bio of Dr Esha Chainani

• 
  Dr. Alan LindemannMD, MS Dr. Alan Lindemann is an obstetrician and maternal mortality expert, who worked as a clinical associate professor at the University of ND. An alumnus of the University of ND and the University of Minnesota, he is a member of the American College of Obstetricians and Gynecologists and the American Medical Association.
  
  Dr. Alan Lindemann is an obstetrician and maternal mortality expert, who worked as a clinical associate professor at the University of ND. An alumnus of the University of ND and the University of Minnesota, he is a member of the American College of Obstetricians and Gynecologists and the American Medical Association.

Reshmi DasMSc

Reshmi Das has over four years of experience as a clinical coordinator, medical content writer and medical conference coordinator. Her continuous interest in medical journals and writing makes her write well-researched articles for MomJunction.

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Rebecca MalachiBSc

Rebecca is a pregnancy writer and editor with a passion for delivering research-based and engaging content in areas of fertility, pregnancy, birth, and post-pregnancy. She did her graduation in Biotechnology and Genetics from Loyola Academy, Osmania University and obtained a certification in ‘Nutrition and Lifestyle in Pregnancy’ from Ludwig Maximilian University of Munich (LMU).

Read full bio of Rebecca Malachi

Aneesha AmonzMSc

Aneesha holds a Bachelor's degree in Biotechnology from USTM, Meghalaya and Master’s degree in Applied Microbiology from VIT, Vellore. With two years of experience, she has worked on different research projects in the field of Food Sciences.

Read full bio of Aneesha Amonz