Supporting Preeclampsia Screening with Calibration Verification and/or Linearity Testing

Preeclampsia is a leading cause of maternal and neonatal complications, contributing to 14% of maternal deaths during childbirth and a significant number of premature births.¹ As clinical laboratories play a pivotal role in early detection and diagnosis, ensuring the accuracy and reliability of blood-based biomarker assays is essential. This is where calibration verification and/or linearity testing — supported by LGC Clinical Diagnostics' VALIDATE^® and AccuTrak™ products — become critical tools in the lab technician’s quality assurance arsenal.

The Clinical Value of Preeclampsia Screening

Preeclampsia typically develops after 20 weeks of gestation and is characterized by hypertension and signs of organ dysfunction. Early detection is vital to prevent severe outcomes for both mother and baby.

Key Biomarkers:

• PlGF (Placental Growth Factor)
• sFlt-1 (Soluble fms-like tyrosine kinase-1)
• sFlt-1/PlGF ratio: A powerful diagnostic and prognostic tool

These biomarkers are recommended by multiple international guidelines (ISUOG, FIGO, ISSHP, NICE) and are used in both first-trimester screening and second/third-trimester diagnostics.

The Role of Calibration Verification and/or Linearity Testing

Accurate measurement of PlGF and sFlt-1 is essential for clinical decision-making. Calibration verification (CalVer) and/or linearity testing ensure that assays perform consistently across the full reportable range.

Why It Matters:

• 100% NPV for ruling out early preeclampsia²
• 75% sensitivity for detecting preterm preeclampsia³
• 62% reduction in unnecessary hospitalizations²
• €692 savings per patient through optimized care pathways²

VALIDATE^® and AccuTrak™ Products: Supporting Reliable Results

LGC Clinical Diagnostics VALIDATE^® and AccuTrak™ products are designed to support laboratories in meeting CLIA and CAP requirements for calibration verification and/or linearity testing.

Key Features:

• Ready-to-use liquid materials
• Multi-analyte panels covering renal, liver, and cardiac markers
• Instrument-specific configurations for major IVD platforms
• MSDRx^® software for real-time data analysis and peer comparison

These products help verify the reportable range and/or linearity of assays measuring critical analytes such as Creatinine, Uric Acid, ALT, AST, and more,  supporting the broader diagnostic picture in preeclampsia evaluation.

Application in Preeclampsia Testing

First Trimester:

• Weeks 10–14: Blood sample analyzed for PlGF as part of a combined screening algorithm
• Treatment: Low-dose aspirin (150 mg) from weeks 11–14 to 36 can reduce preterm preeclampsia by 62%.⁴

Second and Third Trimesters:

• Weeks 20–37: sFlt-1/PlGF ratio used to assess risk in symptomatic patients⁵
• Interpretation:
  • ≤38: Low risk
  • 38–<85 (or <110): Intermediate risk
  • ≥85 (or ≥110): High risk

VALIDATE^® and AccuTrak™ products ensure that the instruments measuring these biomarkers are performing within expected parameters, helping labs deliver results clinicians can trust.

Conclusion

Preeclampsia screening is a high-stakes application where assay accuracy directly impacts patient outcomes. By integrating VALIDATE^® and AccuTrak™ calibration verification and/or linearity products into routine quality assurance protocols, laboratory technicians can confidently support clinicians in making timely, informed decisions for maternal and fetal care.

Want to ensure your lab’s assays meet the highest standards for accuracy and reliability?
Explore how VALIDATE^® and AccuTrak™ products can support your calibration verification and linearity testing needs.

References

1. NICHD – Risks of Preeclampsia to the Mother
2. Zeisler, H. – Implementation of the sFlt-1/PlGF Ratio for Prediction and Diagnosis of Pre-eclampsia in Singleton Pregnancy
3. Washington University School of Medicine – Preeclampsia sFlt-1/PlGF Ratio
4. NICHD – An Aspirin a Day for Preeclampsia Prevention
5. Roche Diagnostics – Elecsys® sFlt-1/PlGF Ratio for Preeclampsia

Additional Sources: 

NICE Guidance DG49

ISUOG Resource on Biomarkers