What are the diagnostic criteria for preeclampsia?

From the Guidelines

Preeclampsia is diagnosed when a pregnant woman develops new-onset hypertension (blood pressure ≥140/90 mmHg) after 20 weeks of gestation, along with either proteinuria (≥300 mg in a 24-hour urine collection or protein/creatinine ratio ≥0.3) or evidence of end-organ damage, as recommended by the most recent guidelines 1.

Diagnostic Criteria

The diagnostic criteria for preeclampsia include:

• New-onset hypertension (blood pressure ≥140/90 mmHg) after 20 weeks of gestation
• Proteinuria (≥300 mg in a 24-hour urine collection or protein/creatinine ratio ≥0.3)
• Evidence of end-organ damage, such as:
  • Thrombocytopenia (platelet count <100,000/μL)
  • Renal insufficiency (serum creatinine >1.1 mg/dL)
  • Impaired liver function (elevated liver enzymes to twice the normal concentration)
  • Pulmonary edema
  • Cerebral/visual symptoms

Severe Features

Severe features of preeclampsia include:

• Blood pressure ≥160/110 mmHg on two occasions at least 4 hours apart
• Thrombocytopenia
• Elevated liver enzymes with right upper quadrant pain
• Progressive renal insufficiency
• Pulmonary edema
• New-onset headache or visual disturbances

Management

Management of preeclampsia depends on gestational age and severity, ranging from close monitoring to delivery, which is the definitive treatment 1. Antihypertensive medications like labetalol, nifedipine, or hydralazine may be used to control blood pressure, and magnesium sulfate is administered to prevent seizures in severe cases 1.

Key Recommendations

Key recommendations for the management of preeclampsia include:

• Automated blood pressure measurement with devices validated for pregnancy and preeclampsia
• Use of dipstick proteinuria testing for screening, followed by quantitative testing by urinary protein-to-creatinine ratio or 24-hour urine collection
• Treatment of severe hypertension with intravenous labetalol, oral nifedipine, or intravenous hydralazine
• Administration of magnesium sulfate for eclampsia treatment and prevention among women with severe preeclampsia
• Delivery at term for preeclampsia, with consideration of preterm delivery for severe cases or fetal distress 1.

From the Research

Diagnostic Criteria for Preeclampsia

The diagnostic criteria for preeclampsia include:

• New-onset hypertension (blood pressure ≥140/90 mmHg) after 20 weeks of gestation 2, 3
• Proteinuria (24-hr urinary protein ≥ 0.3 g) or any indication of end-organ damage 3
• End-organ damage may include liver and kidney dysfunction, thrombocytopenia, pulmonary edema, and neurologic dysfunction 3, 4

Biomarkers for Preeclampsia

Some biomarkers that may be used to diagnose preeclampsia include:

• Serum uric acid levels, which may indicate kidney dysfunction and predict the severity of preeclampsia 3
• Liver function tests, such as alanine aminotransferase (ALT) and aspartate aminotransferase (AST), which may indicate liver damage and predict adverse outcomes 3, 5

Evolution of Diagnostic Criteria

The diagnostic criteria for preeclampsia have evolved over time, with a shift from a focus on hypertension, edema, and proteinuria to a focus on hypertension and organ dysfunction 6

• The current criteria include a blood pressure cutoff of ≥140/90 mmHg and evidence of end-organ damage, such as proteinuria or elevated liver enzymes 2, 3
• However, there is ongoing debate about the optimal diagnostic criteria, including the use of flow-charts and decision trees to guide diagnosis 6

Severe Features of Preeclampsia

Severe features of preeclampsia may include:

• Elevated liver enzymes, such as AST or ALT ≥2x the upper limit of normal 5
• However, the association between elevated liver enzymes and adverse outcomes is not fully understood, and further research is needed to guide diagnosis and management 5