What is the definition of postpartum preeclampsia?

Definition of Postpartum Preeclampsia

Postpartum preeclampsia is defined as the new onset of hypertension (blood pressure ≥140/90 mmHg) and either proteinuria or evidence of maternal organ dysfunction occurring after delivery, typically within 48 hours to 6 weeks postpartum, in a previously normotensive woman. 1

Diagnostic Criteria

Essential Components:

• Blood pressure ≥140/90 mmHg measured on at least two separate occasions, at least 15 minutes apart 2
• Plus at least one of the following:
  • Proteinuria (≥0.3g/24h or albumin-to-creatinine ratio ≥30 mg/mmol) 2
  • Evidence of maternal organ dysfunction 3:
    • Renal insufficiency
    • Liver involvement
    • Neurological complications (e.g., headache, visual disturbances)
    • Hematological complications
    • Uteroplacental dysfunction

Timing:

• Most commonly occurs within the first 7-10 days after delivery 1, 4
• Can occur from 48 hours up to 6 weeks postpartum 1
• Rare cases have been reported up to 12 weeks postpartum 5

Severe Features of Postpartum Preeclampsia

Severe postpartum preeclampsia is characterized by:

• Severe hypertension: SBP ≥160 mmHg or DBP ≥110 mmHg 2, 3
• Neurological symptoms: Persistent headache, visual disturbances, seizures (eclampsia)
• HELLP syndrome: Hemolysis, elevated liver enzymes, low platelets
• Pulmonary edema
• Acute kidney injury

Pathophysiology

The pathophysiology of postpartum preeclampsia involves:

• Withdrawal of placentally secreted vasodilatory hormones after delivery 2
• Increase in systemic vascular resistance and BP rise, with peak systolic BP occurring on days 3-5 postpartum 2
• Peak diastolic BP occurring on days 5-7 postpartum 2
• Rapid volume shifts and mobilization of interstitial fluid 2

Risk Factors

Common risk factors include:

• Older maternal age
• Black race
• Maternal obesity
• Cesarean delivery 1
• Previous preeclampsia
• Chronic hypertension
• Pre-existing diabetes
• Renal disease
• Autoimmune disorders 3

Clinical Presentation

Most common presenting symptoms:

• Headache (most frequent neurological symptom) 4
• Visual changes
• Hypertension
• Edema
• Dyspnea (atypical but reported) 4
• Seizures (in eclampsia) 6, 7

Important Distinctions

1. De novo vs. persistent: Postpartum preeclampsia can develop de novo in previously normotensive women or as a continuation of antepartum preeclampsia 1

2. Late postpartum eclampsia: Seizures occurring beyond 48 hours after delivery in women with preeclampsia, can present up to 1 month postpartum 7

3. Timing of BP normalization: In women without HDP, BP should normalize by 2 weeks postpartum 2

Clinical Implications

• Postpartum preeclampsia may be associated with higher maternal morbidity than antepartum-onset preeclampsia 1
• Ten percent of maternal deaths due to hypertensive disorders occur in the postpartum period 2, 3
• Women with a history of preeclampsia require long-term follow-up due to increased cardiovascular risk 3

Management Considerations

• Antihypertensive medications
• Magnesium sulfate for seizure prophylaxis
• Diuretics may be considered 1, 4
• Monitor BP at least 4-6 hourly for at least 3 days postpartum 2
• Avoid NSAIDs if possible, especially with acute kidney injury 2

Understanding this definition and diagnostic framework is crucial for timely recognition and management of this potentially life-threatening condition.