What classifies preeclampsia with severe features in a pregnant patient with elevated blood pressure: a) impaired renal function, b) thrombocytopenia, c) protein/creatinine ratio > 0.3, or d) right lower quadrant pain?

Preeclampsia with Severe Features: Diagnostic Criteria

The correct answer is (a): elevated creatinine (1.1 mg/dL or 2X baseline) classifies preeclampsia with severe features. 1

Severe Features Defined

Preeclampsia with severe features requires the presence of any one of the following criteria in addition to the baseline diagnosis of preeclampsia 1:

Renal Dysfunction

• Serum creatinine >1.1 mg/dL or doubling of baseline creatinine 1
• This threshold is specifically chosen because it represents significant renal impairment in the context of pregnancy, where normal creatinine levels are typically lower than non-pregnant values 2

Hematologic Abnormalities

• Platelet count <100,000/µL (not <150,000 as listed in option b) 1
• The threshold of 100,000/µL represents clinically significant thrombocytopenia that indicates severe disease 2
• Platelets <150,000/µL may indicate mild thrombocytopenia but does not meet criteria for severe features 1

Hepatic Involvement

• Liver transaminases ≥2 times the upper limit of normal 1
• Severe persistent right upper quadrant or epigastric pain (not right lower quadrant as in option d) 2, 1
• This pain results from liver capsule distension due to hepatic edema and potential hemorrhage 2

Cardiovascular Manifestations

• Systolic BP ≥160 mmHg or diastolic BP ≥110 mmHg 1
• Pulmonary edema 1

Neurological Features

• New-onset cerebral or visual disturbances (headache unresponsive to medication, blurred vision, scotomata, cortical blindness) 2, 1
• These symptoms indicate cerebral edema and increased risk of eclamptic seizures 2

Why the Other Options Are Incorrect

Option (b): Platelets <150,000

• This represents mild thrombocytopenia, not a severe feature 1
• The cutoff for severe features is <100,000/µL 1
• While <150,000 warrants monitoring, it alone does not classify the disease as severe 2

Option (c): Protein/Creatinine Ratio >0.3

• This threshold (>0.3 or >30 mg/mmol) is used to diagnose preeclampsia, not to classify severity 2
• The degree of proteinuria does not correlate with disease severity or outcomes 1
• Current guidelines explicitly state that proteinuria level should not be used to determine timing of delivery or severity classification 2

Option (d): Right Lower Quadrant Pain

• The location is incorrect—severe preeclampsia causes right upper quadrant or epigastric pain, not right lower quadrant pain 2, 1
• This pain pattern is specific because it reflects hepatic involvement (liver capsule distension) 2
• Right lower quadrant pain would suggest alternative diagnoses (appendicitis, ovarian pathology) rather than preeclampsia complications 2

Critical Clinical Pitfall

Do not wait for multiple severe features to develop before classifying as severe preeclampsia. The presence of even a single severe feature mandates immediate management as severe disease, including consideration for magnesium sulfate prophylaxis, aggressive blood pressure control, and delivery planning 2, 1. All preeclampsia can rapidly progress to life-threatening emergencies regardless of initial classification 2, 3.