Definitions: (Wagner 2004)

Preeclampsia: a pregnancy-specific, multisystem disorder that is characterized by the development of hypertension and proteinuria after 20 weeks of gestation. Preeclampsia can occur anytime within the antepartum, intrapartum, and even postpartum periods.

  • Preeclampsia superimposed on chronic hypertension: new onset proteinuria, an acute increase in the level of hypertension, or development of HELLP syndrome in the setting of chronic hypertension
  • HELLP Syndrome: Complication of preeclampsia characterized by hemolysis, elevated liver enzymes, and a low platelet count

Eclampsia: a severe complication of preeclampsia in which a woman has the new onset of seizures

Chronic hypertension: elevated blood pressure that predates the pregnancy, is documented before 20 weeks of gestation, or is present 12 weeks after delivery.

Gestational hypertension: elevated blood pressure without proteinuria which develops after 20 weeks of gestation and blood pressure returns to normal within 12 weeks after delivery

Pre-eclampsia Pathophysiology


  • Pathophysiology of preeclampsia remains controversial
  • Most theories center around abnormal placentation and immunologic factors
  • Fetal Pathophysiology (Uzan 2011)
    • Increased uterine arterial resistance and higher sensitivity to vasoconstriction causes chronic placental ischemia
    • Leads to fetal complications including intrauterine growth restriction and intrauterine death


  • Hypertensive disorders of pregnancy complicate 10% of pregnancies worldwide (Aronow 2017)
  • Among the most common causes of maternal and perinatal morbidity and mortality
  • Eclampsia occurs in less than 1% of women with preeclampsia (Witlin 1998).

Risk Factors: (RCOG 2010)

High-Risk Factors Moderate-Risk Factors
Hypertensive disease during

previous pregnancy

First Pregnancy
Chronic kidney disease Age > 40
Autoimmune Conditions (i.e. SLE,

antiphospholipid syndrome)

Pregnancy Interval > 10 years
Diabetes Mellitus BMI > 35 kg/m2 (at 1st visit)
Chronic Hypertension Family History of Preeclampsia
Multiple Gestations

Clinical Presentation

  • Epigastric/RUQ pain
  • Severe or persistent headache
  • Visual disturbances including blurred vision, double vision, “spots” in vision, photophobia
  • Nausea or vomiting
  • Shortness of breath
  • Increased edema in the extremities or weight gain

Diagnosis: (ACOG 2013)

Necessary lab work: CBC, Basic metabolic panel, LFTs, Urinalysis (24 hour urine collection ideal but impractical in ED), Uric Acid, LDH

Mild Preeclampsia

  • New onset elevated blood pressure ( 140 mmHg OR 90 mmHg diastolic) on two occasions at least 4 hours apart AND
  • Proteinuria (defined as >300mg in 24hr urine collection or protein/creatinine ratio of at least 0.3)

Severe Preeclampsia

  • BP > 160/110
  • 2 + protein on urine dipstick
  • Any concerning signs, symptoms or lab abnormalities
    • Signs/symptoms: headache, visual disturbance, pulmonary edema, oliguria
    • Transaminitis, thrombocytopenia, elevated creatinine

Postpartum Preeclampsia + Eclampsia

  • Most cases occur within 48 hours after delivery, though some patients may present later
  • Suspect in any recent postpartum patient with new onset hypertension, headache or seizure activity

In the absence of proteinuria, the diagnosis of preeclampsia can be made by:

  • Thrombocytopenia (<100,000/microliter)
  • Transaminitis (2x normal value)
  • Serum creatinine > 1.1mg/dL OR doubling of serum creatinine in the absence of other renal disease
  • Pulmonary edema
  • New onset cerebral or visual disturbances

Absence of symptoms AND labs unremarkable

  • Gestational hypertension if >20 weeks gestational age
  • Chronic hypertension at <20 weeks gestational age.

In a patient presenting with preeclampsia < 20 weeks gestation, antiphospholipid syndrome or molar pregnancy should be considered (Aronow 2017).

Note: Urine dipstick is discouraged for purposes of diagnosis of preeclampsia. However, if use of a dipstick is necessary, 1+ is considered the cutoff for proteinuria.

Management (ACOG 2013)

Mild Preeclampsia

  • Assess for features of severe preeclampsia
  • Ultrasound to assess fetal growth and heart rate
  • No emergent blood pressure management indicated (ACOG 2013)
    • SBP < 160 Hg, DBP < 110 mm Hg
    • Antihypertensives may decrease progression to severe preeclampsia but associated with low birth weight
  • Delivery of the fetus and placenta
    • Only curative treatment (Lambert 2014)
    • Recommended in mild preeclampsia at > 37 weeks gestation
      • Mild gestational hypertension or preeclampsia at > 37 weeks gestation
      • Preeclampsia with severe features at > 34 weeks gestation or before fetal viability
  • Expectant management
    • Preeclampsia without severe features < 37 weeks gestation
    • Serial assessment of maternal symptoms and fetal movement
    • Serial blood pressure measurements (2x weekly)
    • Serial weekly platelet count and liver enzymes

Severe Preeclampsia

  • Magnesium sulfate (MgSO4)
    • Role: seizure prophylaxis
    • Dose
      • Intravenous/Intraosseous
        • Loading dose: 4-6 g
        • Maintenance dose: 1-2 g/hr
      • Intramuscular (Pritchard regimen)
        • Loading dose: 4g IV + 10g IM
        • Maintenance dose: 5g IM q4h
    • Blood pressure management
      • Prevents cardiovascular, renal, and cerebrovascular complications
      • Emergency management
        • Labetalol 5-10 mg IV (slow push)
        • Hydralazine 10-20 mg IV (slow push)
        • Nifedipine 100-200 mg PO
      • No significant differences in efficacy or safety between hydralazine, labetalol, or oral nifedipine (ACOG 2013)
    • Emergency delivery
      • Recommended if > 34 weeks gestation or if prior to fetal viability
      • If fetus viable but < 34 weeks obstetrics will likely recommend delayed delivery (24-48 hours) to allow for corticosteroid administration to hasten fetal lung maturation


  • Address ABCs
    • Consider RSI to ensure oxygenation + ventilation
    • Place in left lateral decubitus position
  • Seizure termination
    • MgSO4: 4-6 g bolus followed by 1-2 g/hour infusion
    • Benzodiazepines and propofol should be considered if seizures refractory to MgSO4 despite potential harm to fetus
  • Hypertension management
    • Labetalol 5-10 mg IV (slow push)
    • Hydralazine 10-20 mg IV (slow push)
  • Emergency delivery


  • Maternal complications (Wagner 2004)
    • HELLP syndrome
    • Eclampsia
    • Pulmonary edema
    • Acute renal failure
    • Placental abruption
    • Disseminated intravascular coagulation (DIC)
  • Fetal complications
    • Intrauterine growth restriction
    • Intrauterine fetal demise
    • Increased risk of cardiovascular disease in growth restricted infants

Take Home Points:

  • Suspect preeclampsia in any pregnant women presenting with epigastric/RUQ pain, severe or persistent headache, visual disturbances, nausea or vomiting, shortness of breath, increased edema or weight gain
  • Evaluate for preeclampsia by looking at the blood pressure, urine for protein and obtaining a panel to evaluate for HELLP syndrome
  • Severe preeclampsia and eclampsia are treated with bolus and infusion of MgSO4
  • Emergency delivery is the “cure” for preeclampsia and eclampsia. Consult obstetrics early for an evaluation for delivery
  • Don’t forget to consider preeclampsia and eclampsia in the immediate postpartum period

Read More

LITFL: Preeclampsia and Eclampsia

LITFL: Eclampsia

EM Curious: ED Management of Severe Preeclampsia

Houry DE, Salhi BA. Acute Complications of Pregnancy. In: Marx, J et al, ed. Rosen’s Emergency Medicine. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014: 178: 2282-2302


Wagner LK. Diagnosis and management of preeclampsia. Am Fam Physician 2004; 70(12):2317-24. PMID: 15617295

Uzan J et al. Pre-eclampsia: pathophysiology, diagnosis, and management. Vasc Health Risk Manage 2011; 7:467-474. PMID: 21822394

Aronow, WS. Hypertensive disorders in pregnancy. Ann Transl Med 2017; 5(12):266. PMID: 28706934

Witlin AG, Sibai BM. Magnesium sulfate therapy in preeclampsia and eclampsia. Obstet Gynecol 1998; 92(5):883–9. PMID: 9794688

Royal College of Obstetricians and Gynaecologists. Hypertension in pregnancy: the management of hypertensive disorders during pregnancy. RCOG Press 2010. PMID: 22220321

American College of Obstetricians and Gynecologists, Task Force on Hypertension in Pregnancy. Hypertension in pregnancy. Report of the American College of Obstetricians and Gynencologists’ Task Force on Hypertension in Pregnancy. Obstet Gynecol 2013; 122(5):1122-31. PMID: 24150027

Lambert G et al. Preeclampsia: an update. Acta Anaesthesiol Belg 2014; 65(4):137-49. PMID: 25622379