2nd 3rd Trimester Preeclampsia Build info

Synonyms

• PREECLAMPSIA 2ND 3RD TRIMESTER
• PRECLAMPSIA 2nd 3rd TRI
• LAB14016

Procedure Name

PREECLAMPSIA 2ND 3RD TRIMESTER

Procedure Master Number

LAB14016

Procedure ID

182897

Clinical Info

The 2nd 3rd Trimester Preeclampsia test is a mid to late trimester prognostic test used to aid in the risk assessment of pregnant women (singleton pregnancies between gestational age 23+0 to 34+6/7 weeks) hospitalized for hypertensive disorders of pregnancy (preeclampsia, chronic hypertension with or without superimposed preeclampsia, or gestational hypertension) for progression to preeclampsia with severe features (as defined by the American College of Obstetricians and Gynecologists (ACOG) guidelines1) within 2 weeks of presentation. 
The test incorporates the maternal serum markers soluble fms-like tyrosine kinase-1 (sFlt-1) and Placental Growth Factor (PlGF).  The ratio of the anti-angiogenic sFlt-1 to the angiogenic PlGF help to inform clinicians which patient would be at higher risk for developing the ACOG classification of PE with severe features. Thereafter, women whose test was positive (i.e. high risk) would receive stepped-up care. The elevation in the sFlt-1/PlGF ratio occurs prior to ACOG defined thresholds for delivery (e.g., LFT elevations, thrombocytopenia abnormal umbilical Doppler), and therefore is useful to step-up appropriate care and intensify surveillance before severe features develop.

Specimen Sources

Specimen Types

Container

Gold Top Serum Separator Tube

Collection Instructions

The specimen draw is from 23w0d to 34w6d gestation.
Collect blood by venipuncture, allow it to clot and separate the serum by centrifugation.
Specimen Volume: 3 ml serum (0.5 ml Min)
Specimen Rejection Criteria:
    Incorrect tube type
    Insufficient volume 
    Gross hemolysis/lipemia
    Out of gestational age range
Patients should avoid intravenous heparin within 24 hours prior to venipuncture.Test should not be performed in women receiving exogenous PlGF-2 or PlGF-3 for therapeutic use at concentration higher than 100 pg/mL.Test should not be performed in multiple pregnancy.

Specimen Volume

3
ml serum (0.5 ml Min)

Transport Instructions

Refrigerate prior to shipping for overnight delivery.
Transport temperature: Ambient

Specimen Stability

6 Days Room Temperature
14 Days Refrigerated

Methodology

Time-Resolved Amplified Cryptate Emission (TRACE). This test is a modification of an FDA approved method.  The performance characteristics were validated/verified by Northwell Health Laboratories. The methods and performance characteristics have been reviewed and approved by the New York State Department of Health.

Days Performed

Monday through Friday.   TAT 1 business day upon receipt

Performing Laboratory

Northwell Core Lab at CFAM

CPT

83520 x 2

PDM

Only Orderable at Locations:

Results

Result Interpretation

sFlt-1/PlGF Ratio  Reference Interval  0-39

If the sFlt-1/PlGF ratio is higher or equal to 40, the pregnant woman would be at high risk for progression to preeclampsia with severe features within 2 weeks.

The woman at high risk for progression to preeclampsia with severe features within 2 weeks would receive stepped up care according to the ACOG guidelines. The elevation in the sFlt-1/PlGF ratio antedates ACOG defined criteria for delivery (e.g., LFT elevations, thrombocytopenia abnormal umbilical Doppler), and therefore is useful to step-up appropriate care and intensify surveillance before severe features develop. A woman with “false positive” result would receive stepped up care and would not be harmed by additional monitoring.

If the sFlt-1/PlGF ratio is lower than 40, the pregnant woman would be at low risk for progression to preeclampsia with severe features within 2 weeks.

The woman at low risk for progression to preeclampsia with severe features within 2 weeks would receive standard of care including expectant management according to the ACOG guidelines. A woman with “false negative” result would continue receive existing standard of care including monitoring of future signs of preeclampsia with severe features.

An interpretive report including the patient's marker levels, ratio and ratio cut-off values will be provided.

A link to the full instructions for use can be found at: https://www.thermofisher.com/diagnostic-education/dam/pct/preeclampsia-training.pdf

Prognostic Performance
The performance estimates to predict PE with severe features* within two weeks using an sFlt-1/PlGf ratio cut-off set equal to 40 is based on the data collected during the PRAECIS clinical study. ²

Sensitivity (95% CI) – 93.5% (89.1 -96.3)
Specificity (95% CI) – 74.9% (70.2 – 79.0)
PPV (95% CI) – 65.2% (59.3 – 70.6)
NPV (95% CI) – 95.8% (92.9 – 97.6)

*Severe features of PE: Systolic blood pressure of 160 mm Hg or higher, or diastolic blood pressure of 110 mm Hg or higher on two occasions at least 4 hours apart while the patient is on bed rest (unless antihypertensive therapy is initiated before this time, thrombocytopenia (platelet count less than 100 × 109/L), impaired liver function as indicated by abnormally elevated blood 
concentrations of liver enzymes (to twice normal concentration), severe persistent right upper quadrant or epigastric pain unresponsive to medication and not accounted for my alternative diagnoses, or both, progressive renal insufficiency (serum creatinine greater than 1.1 mg/dL or a doubling of the serum creatinine concentration in the absence of other renal disease), pulmonary edema, new-onset cerebral or visual disturbances, headache unresponsive to medication and not accounted for by alternative diagnoses. Women with gestational hypertension or chronic hypertension who developed new evidence of thrombocytopenia, impaired liver function, renal insufficiency, pulmonary edema, visual loss or cerebral disturbances as described above were considered to have preeclampsia with severe features.

Disclaimers
The sFlt-1/PIGF ratio has been validated specifically for predicting risk that preeclampsia will progress to severe features within 2 weeks of presentation. It has not been validated for any other purpose. The test is not intended to replace standard of care recommendations defined by the ACOG standard.

Warnings and Precautions
The sFlt-1/PlGF ratio is indicated to be used as an aid in the management of the patient and is a prognostic assay intended to stratify hospitalized patients in two risk groups (low risk and high risk of progression to preeclampsia with severe features within two weeks from presentation). The assay results should only be used in conjunction with information available from clinical evaluations and other standard of care procedures. The test result is not to be used to replace clinical judgement. 

The same patient sample must be used to run both sFlt-1 and PIGF. The analyte test results are not intended to be used individually. 

This test including the clinical cut off and performance characteristics are based on the  BꞏRꞏAꞏHꞏMꞏS sFlt-1 KRYPTOR and BꞏRꞏAꞏHꞏMꞏS PIGF plus KRYPTOR.  Use of another manufacturer’s clinical cutoff should not be used and may result in erroneous results; for example false positive or false negative. 

This test should NOT be used in the following circumstances  because the safety and effectiveness of the device has not been established:

•    multiple pregnancy
•    women receiving intravenous heparin within 24 hours of testing
•    women receiving exogenous PlGF-2 or PlGF-3 for therapeutic use at concentration higher than 100 pg/mL

The clinical management of each patient should be dependent on the patient’s health care provider’s recommendations as inferred from their clinical status. Therefore, the sFlt-1/PlGF ratio should not be used as a deciding factor to change management plans, especially discharge from hospital or delivery decisions.

Clinical References 
1.  Gestational Hypertension and Preeclampsia: ACOG Practice Bulletin, Number 222.Obstet Gynecol, 2020; 135(6): p. e237-e260.
2. Thadhani et al., Circulating Angiogenic Factor Levels In Hypertensive Disorders of Pregnancy. NEJM, 2022;1 (12), EVIDoa220016.

Forms

• Technical Bulletin Preeclampsia 2nd 3rd Trimester Test Update 04-02-2025