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Preeclampsia and HELLP Syndrome Tests: Understanding Blood and Urine Results

September 18, 2026
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How blood pressure, urine protein, platelets, liver enzymes, and creatinine help clinicians distinguish gestational hypertension, preeclampsia, and HELLP syndrome.

Pregnant woman with her heart, liver, and kidneys highlighted, wearing a blood-pressure cuff beside blood and urine specimens.
Blood pressure measurements and blood and urine testing provide complementary information about maternal health. An obstetric team interprets the findings with symptoms and the pregnancy or postpartum context.

Preeclampsia tests help an obstetric team evaluate how pregnancy-related hypertension is affecting the body. Blood and urine results answer different questions: urine protein can reveal kidney involvement, blood counts measure platelets, chemistry tests assess kidney and liver changes, and additional studies look for red blood cell breakdown when HELLP syndrome is suspected. Results must be considered with blood pressure, symptoms, pregnancy timing, prior measurements, and fetal assessment.

A normal laboratory report does not make severe blood pressure or concerning symptoms safe. Preeclampsia can occur without significant protein in the urine, and HELLP can have an atypical presentation. Testing should support prompt obstetric care.

An obstetric clinician reviews lab results with a pregnant patient wearing a blood pressure cuff; blood and urine samples are on the desk.
Preeclampsia tests are interpreted alongside blood pressure, symptoms, pregnancy timing, and the obstetric assessment.

When to seek immediate medical care

During pregnancy or after delivery, seek immediate obstetric or emergency assessment for a blood pressure reading of 160 systolic or higher, or 110 diastolic or higher. Either number can reach the severe range. Do not wait for an outpatient blood draw, a 24-hour urine collection, or four hours of home readings before seeking help. Clinicians confirm severe readings promptly and determine treatment.1

Urgent warning symptoms include a severe or persistent headache, vision changes, severe upper abdominal pain, chest pain, difficulty breathing, fainting, or sudden marked swelling of the face or hands. Reduced fetal movement also requires immediate obstetric assessment. Call 911 for a seizure, stroke symptoms, collapse, severe breathing difficulty, or another life-threatening emergency. Symptoms deserve assessment even if a blood pressure reading is unavailable.2

For a new reading of 140 systolic or higher, or 90 diastolic or higher, contact your prenatal team promptly and follow its instructions. Do not interpret the lower threshold as permission to wait when symptoms are concerning.

A pregnant patient with a headache is helped into medical care; the message says not to wait for lab results.
Severe blood pressure or concerning symptoms during pregnancy or after delivery require immediate obstetric or emergency assessment. Do not wait for outpatient lab results.

How this guide fits with prenatal testing

For routine testing and trimester timing, see Pregnancy Blood Tests and Prenatal Screening. For general prenatal care and warning signs, see Healthy Pregnancy: Essential Steps, Tests, and Warning Signs. This article focuses on understanding an obstetric evaluation for hypertension, preeclampsia, or HELLP.

A July 2026 CDC report found that the birth-certificate category called gestational hypertension increased from 6.0% of U.S. births in 2016 to 10.4% in 2024. That surveillance category includes pregnancy-induced hypertension and preeclampsia; it is broader than the clinical diagnosis of gestational hypertension described below.3

How gestational hypertension, preeclampsia, and HELLP differ

Gestational hypertension is new hypertension after 20 weeks in someone whose blood pressure was previously normal, without proteinuria or other findings establishing preeclampsia. For nonsevere readings, confirmation generally uses two measurements at least four hours apart. Ongoing surveillance matters because the condition can change.

Preeclampsia involves pregnancy-related hypertension with qualifying proteinuria or other qualifying organ involvement. It can also develop on top of chronic hypertension, which is called superimposed preeclampsia. Hypertension known before pregnancy or identified before 20 weeks usually belongs to the chronic-hypertension assessment.4

Severe-range gestational hypertension is a critical exception: ACOG classifies confirmed severe-range gestational hypertension as preeclampsia with severe features. Additional abnormal urine or blood results are not required to make the blood pressure dangerous.1

HELLP syndrome refers to hemolysis, elevated liver enzymes, and low platelets. Hemolysis means red blood cells are breaking down. HELLP is a serious obstetric complication that often accompanies preeclampsia, but the usual blood-pressure or urine-protein pattern may be incomplete. It can develop during pregnancy or after birth.5

Which blood and urine tests are used for preeclampsia?

The obstetric team commonly reviews a platelet-containing blood count, serum creatinine, liver enzymes, and quantified urine protein. The exact order depends on the presentation and care setting. The tests below explain the evaluation; they are not a universal self-order list.

Blood pressure, urine protein, platelets, liver enzymes, and serum creatinine connect to clinical assessment; symptoms and timing also matter.
Blood pressure, urine protein, platelets, liver enzymes, and serum creatinine answer different questions. Clinicians interpret them together with symptoms and pregnancy timing.

Blood count and platelet testing

A Complete Blood Count with Differential and Platelets measures several blood-cell populations, including platelets. Platelets help blood clot. A low count has multiple possible explanations, so clinicians review its timing, previous counts, symptoms, and accompanying liver or hemolysis findings.

The rate of change matters. A count that has fallen substantially since a recent draw may need attention even before reaching a diagnostic threshold. Mild isolated thrombocytopenia can occur during pregnancy, but it should not be assumed to be harmless when blood pressure, symptoms, or other results are changing.

Serum creatinine and kidney assessment

A Creatinine Test measures a waste product cleared by the kidneys. Pregnancy normally lowers serum creatinine, so an increase can be clinically meaningful even when the result remains inside a nonpregnant adult reference interval. Earlier pregnancy values help the team understand whether the current result represents deterioration.

Standard estimated glomerular filtration rate calculations, or eGFR, are not valid for assessing kidney function during pregnancy. If eGFR appears automatically on a report, it should not be used as reassurance. Pregnancy kidney assessment relies on serum creatinine and the clinical picture.6

Liver enzymes and chemistry panels

An AST Test and an ALT Test measure enzymes that can rise with cell injury. The obstetric team compares the values with the laboratory's upper reference limits and evaluates symptoms, particularly persistent upper abdominal pain. Elevated enzymes do not identify the cause by themselves; medication effects, hepatitis, gallbladder disease, and other conditions can require consideration.

A Comprehensive Metabolic Panel Test includes creatinine, AST, and ALT among other measurements. It does not include a platelet count or quantify urine protein. When a panel already provides the required chemistry measurements, ordering the same individual tests again may duplicate testing. A panel containing kidney markers also does not overcome the limitations of eGFR in pregnancy.

What do urine protein results mean?

The Protein Total Random Urine Test with Creatinine measures total protein and creatinine in one urine specimen and reports their ratio. This helps account for how concentrated the sample is. The urine creatinine used in that calculation serves a different purpose from serum creatinine.

A urine specimen sits beside a report listing total protein, urine creatinine, and the protein-to-creatinine ratio.
A spot urine test measures total protein and urine creatinine and reports their ratio. Urine protein results must be interpreted with the rest of the obstetric assessment.

In the U.S. ACOG framework, a protein-to-creatinine ratio of 0.3 mg/mg or higher, equivalent to 300 mg/g or higher, supports the proteinuria criterion. Check the units: a ratio is not the same as a standalone protein concentration. The result does not diagnose preeclampsia without the appropriate clinical context.1

A lower ratio does not exclude preeclampsia when other qualifying features are present. A result near a cutoff, an unexpected result, or an uncertain specimen may require reassessment. Urinary infection, blood contamination, and preexisting kidney disease can complicate interpretation.

When a 24-hour urine collection or urinalysis helps

A Protein Total 24 Hour Urine Test with Creatinine can quantify protein over a full day when the clinician needs that approach. ACOG accepts at least 300 mg of protein in 24 hours as qualifying proteinuria. A spot ratio can often answer the initial question without waiting a day; both methods are not automatically needed.1

Follow the collection instructions precisely and report missed samples. Urinalysis with Reflex to Microscopic provides different information about urine chemistry and sediment. Dipstick protein is less reliable than quantitative testing; a negative dipstick cannot independently rule out disease.

How combined results change the interpretation

The following examples are fictional and simplified. They illustrate questions for the obstetric team, not a tool for self-diagnosis. Assume new hypertension after 20 weeks unless the example states otherwise. Diagnostic interpretation must account for alternative explanations.

Combined findingsWhat the pattern raisesWhy the next step matters
Confirmed nonsevere hypertension with no qualifying proteinuria, reassuring blood tests, and no severe symptomsGestational hypertension may fit the current assessment.Continue obstetric surveillance; an initial reassuring evaluation does not guarantee stability.
Confirmed hypertension with a urine protein-to-creatinine ratio of 0.45 mg/mgThe proteinuria criterion is met.The clinician assesses for preeclampsia and checks for severe features.
Hypertension, little urine protein, and platelets below 100,000/µLA severe hematologic feature may be present.Urgent assessment is needed; significant proteinuria is not required.
Hypertension with creatinine above 1.1 mg/dL or doubled from baseline, without another renal explanationA severe kidney feature may be present.Urgent obstetric assessment and evaluation of the cause are needed.
Hypertension with AST or ALT exceeding twice the laboratory upper limit, without another explanationA severe liver feature may be present.Review symptoms, platelets, and possible hemolysis urgently.
Falling platelets, rising liver enzymes, and evidence of red-cell breakdownHELLP is a concern.Immediate hospital assessment is needed, even when the usual pressure or protein pattern is incomplete.
Severe-range blood pressure with otherwise reassuring laboratory resultsThe pressure itself establishes a serious concern.Do not wait for another abnormal result before seeking emergency obstetric care.

Severe features can also include pulmonary edema, visual disturbances, or a new headache that does not respond to medication and is not explained by another condition. Persistent severe upper abdominal pain can be significant even when blood-test changes are limited. A laboratory threshold is not a boundary below which symptoms can safely be ignored.1

What additional tests help evaluate HELLP syndrome?

HELLP connects hemolysis, elevated liver enzymes, and low platelets, with a reminder that urgent clinical assessment is essential.
HELLP refers to hemolysis, elevated liver enzymes, and low platelets. The combined findings require urgent clinical assessment.

HELLP syndrome tests investigate whether low platelets and liver changes are accompanied by hemolysis. Clinicians may add a Lactate Dehydrogenase Test, a Bilirubin Fractionated Test, and a Haptoglobin Test. They may also request microscopic examination of a peripheral blood smear to look for fragmented red cells.

LDH can rise with tissue injury and red-cell breakdown, but it is nonspecific. Fractionated bilirubin helps distinguish direct and indirect bilirubin; increased indirect bilirubin can support a hemolysis assessment. Haptoglobin binds free hemoglobin and may fall when red cells break down. Each finding has other possible explanations. Their agreement with the platelet count, liver enzymes, symptoms, and clinical course is what makes the assessment useful.10, 11

If bleeding or disseminated intravascular coagulation is a concern, clinicians may obtain Prothrombin with INR and Partial Thromboplastin Times and Fibrinogen Activity testing. These assess aspects of clotting and are conditional additions, rather than routine screening for every pregnancy. Hospital teams coordinate any further testing, blood-product needs, maternal stabilization, fetal assessment, and delivery decisions.1, 5

Why baseline values and repeat results matter

Record the collection date and time beside each result. A platelet count from last week and liver enzymes from today may not describe the same stage of illness. Ask which values are changing together and whether the change affects the care plan.

For example, a fictional creatinine increase from 0.55 to 0.88 mg/dL merits comparison with the pregnancy baseline, even though neither number exceeds 1.1 mg/dL. That change is not, by itself, a diagnosis. It is a reason for the team to assess the trend, timing, and possible causes.

People who enter pregnancy with hypertension, proteinuria, kidney disease, or lupus need particular attention to earlier records. New organ dysfunction or a substantial change in the established pattern may prompt evaluation for superimposed preeclampsia. Specialist review helps distinguish overlapping conditions.6

Repeat-test timing follows clinical severity, symptoms, gestational age, fetal findings, and previous results. A scheduled repeat draw should never delay assessment of new symptoms. For help comparing reference intervals, units, and trends, read How to Read and Understand Your Lab Results.

What can complicate or mislead the interpretation?

  • One abnormal marker: Low platelets, proteinuria, and elevated liver enzymes each have several possible causes. They do not automatically establish HELLP or preeclampsia.
  • Collection problems: An incomplete timed urine collection, contaminated urine, or a laboratory specimen-quality warning can change what a result means. Report the issue; do not dismiss a potentially serious result yourself.
  • Uric acid: A Uric Acid Test is not a standalone diagnostic or rule-out test for preeclampsia and should not replace the core assessment.
  • Another illness: Thrombotic thrombocytopenic purpura, other thrombotic microangiopathies, acute fatty liver of pregnancy, lupus activity, and other disorders can resemble parts of the pattern. An atypical course needs specialist investigation.
  • An incomplete assessment: Blood and urine tests do not measure fetal well-being, locate placental problems, determine delivery timing, or replace examination and blood-pressure monitoring.

Provide the care team with your medication and supplement list and any history of kidney, liver, blood, or autoimmune disease. Do not start aspirin, stop prescribed medication, or change treatment because of a laboratory result without obstetric guidance.

Where do sFlt-1 and PlGF tests fit?

The sFlt-1/PlGF ratio assesses the balance between two placental-related proteins. It has a specialized role in estimating short-term risk in selected patients. ACOG's 2024 clinical update addresses its use in certain pregnant patients hospitalized with hypertensive disorders.7

For example, the FDA clearance reviewed for the Roche Elecsys assay specifies hospitalized patients with a singleton pregnancy at 23 weeks through 34 weeks and 6 days, to help assess progression to preeclampsia with severe features within two weeks. It is used with clinical assessment and routine tests. The assay, population, and intended use determine interpretation; its cutoff is not a universal diagnostic threshold.8

This specialist assessment should not be presented as an independent consumer screen or a reason to disregard severe blood pressure, symptoms, or organ abnormalities.

Why follow-up continues after delivery

Delivery does not immediately end the need for surveillance. Preeclampsia can first appear after childbirth, and blood pressure or organ abnormalities can persist. Before discharge, ask for a written plan identifying when to check blood pressure, when laboratory tests are due, who reviews them, and where to go if symptoms develop.4

A postpartum parent reviews blood pressure, lab follow-up, and care-contact notes while a partner holds the newborn.
Follow-up after delivery should identify blood-pressure checks, needed lab tests, and who reviews the results. New or worsening symptoms require assessment according to their urgency.

Keep scheduled follow-up even if you feel better. Persistent kidney or urine abnormalities may need further evaluation. Tell emergency clinicians that you recently gave birth; severe headache, vision changes, chest pain, or difficulty breathing should not be attributed automatically to sleep loss or routine recovery.2

A history of pregnancy-related hypertension also matters to future cardiovascular care. Once the acute condition has resolved, preserve that history in your medical record and discuss ongoing prevention with your clinician. See Women's Heart Health Blood Tests for pregnancy-history follow-up and the Heart Health Blood Tests pillar for broader cardiovascular testing.9

Questions to ask your obstetric team

  • Which diagnosis best fits my blood pressure, symptoms, and results today?
  • Are my platelets, creatinine, or liver enzymes changing from baseline?
  • Does my urine result use mg/mg, mg/g, or another unit?
  • Is a repeat specimen needed, and who will review it?
  • Is there evidence of hemolysis or another condition that needs investigation?
  • What symptoms or blood-pressure readings require immediate care?
  • What is my postpartum blood-pressure and laboratory follow-up plan?

Frequently asked questions

Can preeclampsia occur without protein in the urine?

Yes. Other qualifying features can establish the diagnosis in the appropriate hypertensive pregnancy. Urine protein should never be used as the only gatekeeper for further evaluation.

Does a normal CBC or metabolic panel rule out preeclampsia?

No. These tests answer only part of the question. They cannot override severe blood pressure, concerning symptoms, or another clinical indication for urgent assessment.

Does everyone need a 24-hour urine collection?

No. A properly interpreted spot protein-to-creatinine ratio can often provide the information needed. The clinician decides whether a timed collection or repeat specimen would answer a remaining question.

Can one elevated LDH result diagnose HELLP syndrome?

No. LDH is nonspecific. HELLP evaluation considers red-cell breakdown alongside platelets, liver findings, symptoms, and the overall clinical picture.

Can I use direct-access testing to monitor suspected preeclampsia?

Suspected preeclampsia requires an obstetric-led plan, with access to timely assessment and treatment. Outside laboratory results may supplement a coordinated plan when appropriate, but elective testing must not delay care. The Direct-Access Lab Testing guide explains ordering and follow-up limitations.

Related reading

Medical references

  1. American College of Obstetricians and Gynecologists. Gestational Hypertension and Preeclampsia. Practice Bulletin No. 222. 2020. Published bulletin hosted by the Preeclampsia Foundation.
  2. Centers for Disease Control and Prevention. Urgent Maternal Warning Signs and Symptoms. 2024.
  3. Gregory ECW. CDC National Center for Health Statistics. Trends and Characteristics in Gestational Hypertension: United States, 2016–2024. National Vital Statistics Reports. July 29, 2026;75(4).
  4. National Library of Medicine. MedlinePlus. High Blood Pressure in Pregnancy; Preeclampsia.
  5. National Library of Medicine. MedlinePlus. HELLP Syndrome.
  6. Wiles K, Chappell L, Clark K, et al. Clinical Practice Guideline on Pregnancy and Renal Disease. BMC Nephrology. 2019;20:401.
  7. American College of Obstetricians and Gynecologists. Clinical Practice Update: Biomarker Prediction of Preeclampsia With Severe Features. 2024. Summary hosted by the Society for Maternal-Fetal Medicine.
  8. U.S. Food and Drug Administration. Elecsys sFlt-1 and Elecsys PlGF: Decision Summary K241453.
  9. Centers for Disease Control and Prevention. High Blood Pressure During Pregnancy.
  10. ARUP Laboratories. Hemolytic Anemias Testing Algorithm. 2022.
  11. American Association for the Study of Liver Diseases. 2026 Hepatology Practice Board Questions. HELLP discussion, question 9.

This article provides education and does not diagnose or treat pregnancy complications. Discuss results with a qualified obstetric healthcare professional. Ulta Lab Tests offers laboratory testing services; commercial test availability does not establish that a test is appropriate for an urgent pregnancy concern.

Recommended Lab Tests

Category Test — candidate Ulta link Role in the article
Blood count and platelets Complete Blood Count with Differential and Platelets Core platelet-containing blood count
Kidney function Creatinine Test Serum kidney marker
Urine protein Protein Total Random Urine Test with Creatinine Spot total-protein-to-creatinine ratio
Urine protein Protein Total 24 Hour Urine Test with Creatinine Timed quantification when indicated
Urine assessment Urinalysis with Reflex to Microscopic Additional urine findings
Liver enzymes AST Test Liver-enzyme assessment
Liver enzymes ALT Test Liver-enzyme assessment
Combined chemistry Comprehensive Metabolic Panel Test Chemistry grouping discussed as an alternative to individual components
Hemolysis Lactate Dehydrogenase Test Conditional red-cell breakdown assessment
Hemolysis Bilirubin Fractionated Test Direct and indirect bilirubin
Hemolysis Haptoglobin Test Additional hemolysis evidence
Coagulation Prothrombin with INR and Partial Thromboplastin Times Conditional bleeding or DIC evaluation
Coagulation Fibrinogen Activity Conditional clotting assessment
Additional marker and limitations Uric Acid Test Discussed for its diagnostic limitations
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