What are the diagnostic criteria for pre‑eclampsia without severe features?

Diagnostic Criteria for Preeclampsia Without Severe Features

Preeclampsia without severe features is diagnosed when new-onset hypertension (≥140/90 mmHg) develops after 20 weeks' gestation in a previously normotensive woman, accompanied by either proteinuria (≥0.3 g/24h or protein/creatinine ratio ≥30 mg/mmol) OR evidence of maternal organ dysfunction or uteroplacental dysfunction, but WITHOUT any criteria that define severe features. 1

Core Diagnostic Requirements

Hypertension Threshold

• Blood pressure must be ≥140 mmHg systolic AND/OR ≥90 mmHg diastolic, confirmed on at least two separate occasions at least 15 minutes apart (for severe range) or over several hours (for non-severe range). 2, 1
• The hypertension must appear after 20 weeks' gestation in a woman who was previously normotensive. 2, 1
• Measurements should be taken with the patient seated, back supported, legs uncrossed, arm at heart level, after 5 minutes of rest, using an appropriately sized cuff (≥33 cm arm circumference requires larger cuff). 1

Proteinuria Criteria (When Present)

• Proteinuria ≥0.3 g/24-hour urine collection OR spot urine protein/creatinine ratio ≥30 mg/mmol (0.3 mg/mg). 2, 1
• Initial screening with dipstick urinalysis: ≥1+ (30 mg/dL) should prompt quantitative testing with protein/creatinine ratio. 2
• Proteinuria is NOT required for diagnosis—it is present in only approximately 75% of preeclampsia cases. 1, 3

Alternative Diagnostic Criteria (When Proteinuria Absent)

When proteinuria is absent, preeclampsia can be diagnosed if hypertension is accompanied by any one of the following: 1, 3

Maternal Organ Dysfunction:

• Renal: serum creatinine ≥1.1 mg/dL or doubling of baseline creatinine 1, 3
• Hepatic: liver transaminases elevated to ≥2 times upper limit of normal 1, 3
• Hematologic: thrombocytopenia with platelet count <100,000/μL 1, 3
• Neurologic: new-onset severe headache unresponsive to medication or visual disturbances (scotomata, photopsia, cortical blindness) 1
• Pulmonary edema 1, 3

Uteroplacental Dysfunction:

• Fetal growth restriction 1
• Abnormal umbilical artery Doppler waveform analysis 1
• Intrauterine fetal death 1

Exclusion of Severe Features

To qualify as preeclampsia WITHOUT severe features, the patient must NOT have any of the following: 1, 3

• Systolic BP ≥160 mmHg OR diastolic BP ≥110 mmHg (despite treatment with multiple antihypertensives) 1
• Platelet count <100,000/μL 1, 3
• Liver transaminases ≥2 times upper limit of normal 1, 3
• Serum creatinine ≥1.1 mg/dL or doubling of baseline 1, 3
• Pulmonary edema 1, 3
• New-onset severe persistent headache or visual disturbances 1, 3
• Severe persistent right upper quadrant or epigastric pain 3
• Progressive thrombocytopenia or progressive renal/liver dysfunction 1
• Non-reassuring fetal status 1

Critical Clinical Caveats

Common Pitfalls to Avoid

• Edema is NOT diagnostic and should not be used as a criterion—it is nonspecific and present in many healthy pregnancies. 4, 1
• Hyperreflexia is NOT a diagnostic criterion—it is a nonspecific finding often present in healthy young women. 1
• The level of proteinuria does NOT predict severity or guide delivery decisions—massive proteinuria (>5 g/24h) correlates with neonatal outcomes but not maternal outcomes. 2, 1
• Serum uric acid should NOT be used as an indication for delivery, though it may be monitored as part of disease assessment. 1

Timing Considerations

• Eclampsia can occur without severe hypertension—34% of eclamptic women had maximum diastolic BP ≤100 mmHg in UK studies. 4, 1
• New hypertension before 32 weeks carries a 50% risk of developing preeclampsia, and at 24-28 weeks is particularly predictive of severe disease. 4, 1
• Preeclampsia can progress to life-threatening complications within approximately 2 weeks of diagnosis, requiring close surveillance. 4, 1

Measurement Technique

• Use a liquid crystal sphygmomanometer when available; if not, use a validated automated device specifically tested in preeclampsia populations (not just pregnancy). 2
• Aneroid devices require regular calibration and may be inaccurate in up to 50% of cases. 2
• For non-severe hypertension (140-159/90-109 mmHg), confirm with repeated readings over several hours before making clinical decisions. 2

Biomarker Adjunct

• sFlt-1/PlGF ratio ≤38 can exclude development of preeclampsia in the following week when the diagnosis is clinically suspected but uncertain. 1