What Blood Test Tests for Preeclampsia?

A preeclampsia blood test is a clinical laboratory analysis that measures specific biomarkers in maternal blood to screen for or diagnose preeclampsia, a hypertensive disorder of pregnancy. The primary blood test for preeclampsia today is the sFlt-1/PlGF ratio test, which evaluates the balance between anti-angiogenic and pro-angiogenic factors. This test, along with standard panels like complete blood count (CBC), liver enzymes, and serum creatinine, helps clinicians identify women at risk before symptoms escalate. At anylabtests.com, we provide direct-access blood testing for these markers, empowering you to monitor your pregnancy health from home.

Understanding Preeclampsia and Its Blood Markers

Preeclampsia affects 5–8% of pregnancies in the United States and remains a leading cause of maternal and fetal morbidity. The condition typically emerges after 20 weeks of gestation and is characterized by new-onset hypertension and proteinuria. However, blood tests can detect subclinical changes weeks before clinical signs appear. The most advanced screening today involves the soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) ratio. An sFlt-1/PlGF ratio below 38 in women before 34 weeks suggests a low risk of developing preeclampsia within the next week, while a ratio above 85 indicates high risk. Other essential lab tests include platelet count (thrombocytopenia is common), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) for liver involvement, and serum creatinine for kidney function.

Key Blood Tests for Preeclampsia Screening

1. sFlt-1/PlGF Ratio Test

This is the most specific blood test for preeclampsia today. It requires a single blood draw and is recommended by the American College of Obstetricians and Gynecologists (ACOG) for women with suspected preeclampsia between 20 and 34 weeks. The test can rule out preeclampsia with 99% negative predictive value when the ratio is low.

2. Complete Blood Count (CBC)

A CBC measures hemoglobin, hematocrit, and platelet count. Platelet counts below 100,000/µL indicate severe preeclampsia or HELLP syndrome (hemolysis, elevated liver enzymes, low platelets).

3. Liver Function Tests (AST, ALT)

Elevated liver enzymes (AST >70 IU/L or ALT >70 IU/L) suggest liver involvement, a hallmark of severe disease.

4. Serum Creatinine and Uric Acid

Serum creatinine above 1.1 mg/dL indicates impaired kidney function. Uric acid levels >5.5 mg/dL are also associated with preeclampsia risk.

When Should You Get a Preeclampsia Blood Test?

• If you have chronic hypertension or a history of preeclampsia in a prior pregnancy.
• If you experience sudden swelling, headaches, or visual changes after 20 weeks.
• If your blood pressure readings exceed 140/90 mmHg on two occasions.
• If you are pregnant with multiples or have diabetes, obesity, or autoimmune conditions.

Interpreting Your Results: A Quick Reference Table

Why Direct-Access Testing Matters today

With the rise of telemedicine and patient-empowered healthcare, many women now order their own blood tests through platforms like anylabtests.com. Direct-access testing allows you to monitor sFlt-1/PlGF ratios without a doctor’s referral, though results should always be discussed with your obstetrician. Today, new FDA-cleared point-of-care devices are emerging, but lab-based blood draws remain the gold standard. Our lab partners use CLIA-certified facilities to ensure accuracy.

CTA: Take Control of Your Pregnancy Health

Ready to check your preeclampsia risk from the comfort of home? Order the sFlt-1/PlGF ratio test or a comprehensive preeclampsia panel at anylabtests.com. Our easy process includes online ordering, a nearby lab visit, and secure digital results within 24–48 hours. Order your preeclampsia blood test today and gain peace of mind with actionable data.