Preeclampsia
EMpowering confident decision-making through preeclampsia RISK ASSESSMENT BIOMARKER Analysis
Preeclampsia is a complication of pregnancy that affects approximately 5% of women worldwide. Clinically, preeclampsia may vary from mild to severe forms and may lead to premature delivery or other serious outcomes, which makes early detection and intervention paramount to successful treatment.
This serum test (Mayo ID: PERA) is the first preeclampsia-specific test that can be used to stratify patients into low or high-risk categories, indicating whether a patient is at risk for developing preeclampsia with severe features. With this information, clinicians can make more informed decisions about hospitalization, monitoring, more frequent checkups, and even early delivery.
Preeclampsia Test menu
Preeclampsia
Although the cause of preeclampsia remains unclear, the syndrome may be initiated by an imbalance of placental factors that induce endothelial dysfunction. sFlt-1 (soluble fms-like tyrosine kinase 1) and PIGF (placental growth factor) are both associated with placental dysfunction and risk of PE during pregnancy. Women with PE have been reported to have increased circulating concentrations of soluble fms-like tyrosine kinase 1 (sFlt-1), an antiangiogenic protein largely produced in the placenta, which is associated with inhibition of vascular endothelial growth factor and placental growth factor (PlGF). During pregnancy, PlGF concentrations typically increase progressively in the first and second trimesters and then decrease toward full term. In contrast, in cases of clinical preeclampsia, sFlt-1 concentrations are significantly increased versus concentrations observed in normal pregnancies, while concentrations of circulating free PlGF are significantly decreased relative to normal pregnancy.
The use of the sFlt-1/PIGF ratio has been shown to be a useful tool to aid in risk assessment of patients with clinical signs and symptoms consistent with the development of preeclampsia with severe features (as defined by the American College of Obstetricians and Gynecologists [ACOG, 2020] guidelines). Based on the data collected during the PRAECIS clinical study, the prognostic performance of the sFlt-1/PIGF ratio using a ratio cutoff of 40 (where if the ratio is greater than or equal to 40, there is a high risk for progression to preeclampsia with severe features), exhibited a sensitivity of 94% and specificity of 75% for the development of PE with severe features within two weeks. The performance of the sFlt-1/PlGF ratio to predict the development of PE with severe features within two weeks was statistically higher than the prognostic performance of other commonly used clinical (highest systolic blood pressure (SBP), highest Diastolic blood pressure (DBP) and laboratory general markers associated with preeclampsia such as AST, ALT, creatinine, and platelets).
New targeted prognostic assays for preeclampsia risk assessment are an important first step toward improving overall maternal health. The comprehensive clinical research behind the new test sets the stage for the use of more biomarkers to assess patient risk, inform care decisions, and improve maternal and fetal outcomes globally.
Key testing
- PERA | Preeclampsia sFlt-1/PIGF (Soluble fms-Like Tyrosine Kinase 1/ Placental Growth Factor) Ratio, Serum
- Aids in risk assessment of patients with clinical signs and symptoms consistent with preeclampsia for the development of preeclampsia with severe features.
- Indicated for use in pregnant women, with singleton pregnancies (gestational age 23 to 34+6/7 weeks) hospitalized for hypertensive disorders of pregnancy (preeclampsia, chronic hypertension with or without superimposed preeclampsia, or gestational hypertension) within two weeks of presentation.
- A sFlt-1/PlGF ratio ≥40 suggests the pregnant woman is at high risk for progression to preeclampsia with severe features within two weeks of presentation.
- A sFlt-1/PlGF ratio <40 suggests the pregnant woman is at low risk for progression to preeclampsia with severe features within two weeks of presentation.
Patient case study: The significance of negative predictive value
Patient background and initial presentation
- Patient age: 31 years, pregnant with first child, presents at ER.
- Gestational age: 12 weeks +5 days.
- Symptoms: Nausea, vomiting, low-grade fever, headache, severe blood pressure (BP) ranges from 170/90–180/100.
- Medical history: No prior hypertension or antihypertensive medication use reported.
Initial evaluation, testing, and treatment
| Parameter | Result |
|---|---|
| Clinical exam | Unremarkable |
| Ultrasound | Normal: No placental abnormalities |
| Routine labs (CBS, CMP, THS, lipids, urine, hCG) | Normal |
| 24-hour urine | 245 mg (upper normal range) |
| Renal Doppler ultrasound | No renal artery stenosis |
| Treatment | Five doses of short-acting antihypertensives given at arrival |
Initial outcome/hospitalization
- The patient was admitted for ongoing BP monitoring and titrated up to 60 mg of nifedipine extended release and 200 mg of labetalol twice daily.
- After two days, the patient’s BP was stable and she was discharged with follow-up appointments in maternal-fetal medicine (MFM) and nephrology.
Ongoing management/testing (24–34 weeks gestation)
| Parameter | Result |
|---|---|
| Hypertension | Recurrent, elevated BP levels required multiple additional hospital admissions for BP monitoring and medication titration. |
| Routine lab tests | Normal CBC, CMP, and urine protein:creatinine levels. |
| Proteinuria testing | Highly elevated 24-hour urine testing result of 1064 mg. |
| sFlt-1:PIGF ratio | Low ratio score of 8, which remained consistent on repeat follow-up tests. |
| Fetal status | Reassuring with no signs of growth restriction. |
| Medication regimen | 24 weeks +4 days gestation: Nifedipine extended release titrated up to 90 mg twice daily. 26 weeks + 4 days gestation: Clonidine 0.2 patch added to regimen. Nifedipine and labetalol were titrated down to 60 mg and 600 mg, respectively. |
Final outcomes
- The patient was diagnosed with superimposed preeclampsia without severe features.
- The low sFlt-1:PlGF ratio and other clinical signs supported outpatient management under close MFM supervision.
- The ratio result was a key factor in empowering the patient’s care team to prolong pregnancy.
- The patient delivered a healthy baby at 34 weeks of gestation.
Clinical impact
- The low sFlt-1:PlGF ratio provided objective reassurance that preeclampsia with severe features was unlikely and guided evidence-based decisions to safely manage the patient as an outpatient and prolong gestation, which enabled the best outcomes for mother and baby.
Highlights
Joshua Bornhorst, Ph.D., explains how Mayo Clinic Laboratories' unique assay identifies pregnant women at risk of developing preeclampsia with severe features. Test results can guide clinical management, to safeguard maternal and neonatal health.
Mayo Clinic Laboratories now offers the first preeclampsia-specific test (Mayo ID: PERA) that can be used to stratify patients into low or high-risk categories, indicating whether a patient is at risk for developing preeclampsia with severe features. With this information, clinicians can make more informed decisions about hospitalization, monitoring, more frequent checkups, and even early delivery.
References
- Centers for Disease Control and Prevention. (2023, June 19). High blood pressure during pregnancy. https://www.cdc.gov/high-blood-pressure/about/high-blood-pressure-during-pregnancy.html
- Khan, R. (2023, Nov. 29). Contributor: more informed management of preeclampsia is necessary. The American Journal of Managed Care. https://www.ajmc.com/view/contributor-more-informed-management-of-preeclampsia-is-necessary
- Thermo Fisher Scientific. (n.d.) Insights on preeclampsia management. Accessed Jan. 24, 2024. https://www.thermofisher.com/procalcitonin/us/en/preeclampsia-fda.html