Preeclampsia

Background

• Preeclampsia and eclampsia are diagnosed after 20wks gestation and <4wk post-partum
  • May occur sooner with gestational trophoblastic disease
• Defined as SBP>140 or DBP>90 in previously normotensive pt AND proteinuria >0.3gm in 24h or persistent proteinuria > 1+ on dipstick
• Only 10% of cases occur prior to 34wk

Risk Factors

• Past history of preeclampsia
• First pregnancy
• Family history of preeclampsia
• Preexisting medical conditions:
  • Pregestational diabetes
  • Blood pressure ≥130/80 mm Hg at the first prenatal visit
  • Antiphospholipid antibodies
  • Body mass index ≥26.1
  • Chronic kidney disease
  • Twin pregnancies
  • Advanced maternal age

Clinical Features

• Edema
• Elevated BP
• With increasing severity pulmonary edema, visual changes, and AMS can develop

Differential Diagnosis

3rd Trimester/Postpartum Emergencies

• Acute fatty liver of pregnancy
• Amniotic fluid embolus
• Chorioamnionitis
• Eclampsia
• HELLP syndrome
• Mastitis
• Peripartum cardiomyopathy
• Postpartum endometritis (postpartum PID)
• Postpartum headache
• Postpartum hemorrhage
• Preeclampsia
• Resuscitative hysterotomy
• Retained products of conception
• Septic abortion
• Uterine rupture

Hypertension

• Hypertensive emergency
• Stroke
• Sympathetic crashing acute pulmonary edema
• Ischemic stroke
• Intracranial hemorrhage
• Preeclampsia/Eclampsia
• Autonomic dysreflexia
• Scleroderma renal crisis
• Acute glomerulonephritis
• Type- I myocardial infarction
• Volume overload
• Urinary obstruction
• Drug use or overdose (e.g stimulants, especially alcohol, cocaine, or Synthroid)
• Renal Artery Stenosis
• Nephritic and nephrotic syndrome
• Polycystic kidney disease
• Tyramine reaction
• Cushing's syndrome
• Obstructive sleep apnea
• Pheochromocytoma
• Hyperaldosteronism
• Hyperthyroidism
• Anxiety
• Pain
• Oral contraceptive use

Diagnosis

Work-Up

• CBC
  • Thrombocytopenia suggests severe disease
• Chemistry
  • Elevated Cr suggests severe disease
• Baseline Mg level
• LFT
  • AST/ALT elevation suggests severe disease
• LDH
  • Elevation suggests microangiopathic hemolysis
• Uric acid level
  • Often elevated in preeclampsia
• UA
  • Proteinuria

ACOG Diagnostic Criteria

In 2013, ACOG has decided to remove proteinuria from the definition of severity of preeclampsia

• Blood Pressure
  • Systolic ≥140 mmHg or diastolic ≥90 mmHg on 2 occasions at least 4 hours apart, after 20 weeks gestation with previously normal BPs
  • Systolic ≥160 mmHg or diastolic ≥110 mmHg, confirmed within a short interval (minutes) to facilitate timely antiHTN meds

AND

• Proteinuria
  • Proteinuria ≥300mg in a 24-hour urine collection
  • Spot protein(mg/dL)/creatinine(mg/dL) ratio ≥0.3
  • 1+ on urine dipstick (if no quantitative measurement is unavailable)

OR

• In the absence of proteinuria, new onset HTN with any severe features:
  • Systolic BP ≥160 or diastolic BP ≥110, 2 occasions, 4 hours apart, while on bed rest (unless antiHTN meds were started before this time)
  • Thrombocytopenia platelets <100,000/mL
  • Elevated LFTS (2x normal concentration), severe persistent RUQ/epigastric pain unresponsive to medications and no alternative diagnosis
  • Progressive renal insufficiency (Cr >1.1mg/dL or doubling of Cr concentration in absence of renal disease)
  • Pulmonary edema
  • New onset cerebral or visual disturbance

Management

• Only definitive treatment is delivery
  • Mild preeclampsia - induction or C-section if > 37 wks; consider close monitoring if 34-37 wks
  • Severe Preeclampsia - induction or C-section independent of gestational age

BP Control

• Lower to Sys 130-150, dia 80-100
  • Labetalol
    • Option 1: Initial 20mg; then doses of 20-80mg q10min to total of 300mg
    • Option 2: Initial 20mg; then IV infusion of 1-2mg/min
  • Nicardipine
    • Initial rate of 5mg/hr and increase by 2.5mg/hr q5min to effect
  • Hydralazine
    • Should not be considered first line therapy
    • 5mg IV over 1-2min; repeat bolus of 5-10mg q20min PRN to total of 30mg

Prevention

• The USPSTF recommends the use of low-dose aspirin (81 mg/d) as preventive medication after 12 weeks of gestation in women who are at high risk for preeclampsia. ( B recommendation)

• Magnesium: For seizure prevention, load 4g IV over 15min followed by 1-2g per hr in coordination with admission by OBGYN
  • Observe for loss of reflexes, respiratory depression

Disposition

• Consult with OB/GYN regarding discharge versus admission
  • Some cases of mild preeclampsia may be candidates for outpatient therapy
    • Close follow up and return precautions is key
    • Repeat lab tests 1-2x per week (platelet count, creatinine, AST)

See Also

• Postpartum Emergencies
• Eclampsia

External Links

LITFL: Pre-eclampsia and Eclampsia