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Evaluation and management of severe preeclampsia

Severe preeclampsia is new onset hypertension in pregnancy after 20 weeks gestation with proteinuria. Treatment is usually delivery to prevent maternal and fetal complications, but delayed delivery can be considered under certain circumstances. 

Diagnosis/definition: Preeclampsia is the new onset of hypertension in pregnancy after 20 weeks gestation with proteinuria in a previously normotensive woman.  Severe features of preeclampsia include any of the following findings:

  • Systolic blood pressure of 160mm Hg or higher, or diastolic blood pressure of 110mm Hg or higher on 2 occasions at least 6 hours apart on bed rest
  • Thrombocytopenia (platelet count less than 100,000/microliter)o Impaired liver function o Fetal growth restriction
  • Oliguria <500 mL in 24 hours
  • Proteinuria ≥5g in a 24 hour urine specimen or ≥3+ on 2 random urine samples collected at least 4 hours apart
  • Cerebral or visual symptoms
  • Pulmonary edema or cyanosis
  • Epigastric or right upper quadrant pain

Epidemiology/Incidence: The incidence of severe preeclampsia ranges from 0.6-1.2% of pregnancies in Western countries. Severe preeclampsia <34 weeks’ gestation complicates 0.3% of pregnancies.

Risk factors/associations: The likelihood of severe preeclampsia is substantially increased in women with a history of preeclampsia, diabetes mellitus, chronic renal disease, anti-phospholipid antibodies, obesity, chronic hypertension, or multifetal gestation.

Complications: Maternal complications include intravascular coagulation, bleeding, organ failure (hepatic and renal) following poor perfusion, seizures, development of HELLP (hemolysis, elevated liver enzymes and low platelet count) syndrome, and mortality.  Fetal complications include growth retardation, mortality, and hypoxia.

Prevention:For women with a medical history of early-onset preeclampsia and preterm delivery at <34 weeks gestation or preeclampsia in more than one prior pregnancy, initiating daily low-dose (60-80mg) aspirin beginning in the late first trimester is suggested.



  • Maternal evaluation should include monitoring of blood pressure, urine output, and signs or symptoms of concern (persistent headache, visual changes, epigastric pain, abdominal tenderness, or vaginal bleeding). Laboratory tests should include a complete blood cell count with platelet count, serum creatinine, and liver enzymes. Urinary protein should be quantitated by a 24-hour urine collection.
  • Initial expectant management should include daily assessment of the complete blood cell count with platelet count and liver and renal functions.  The frequency of subsequent laboratory testing can be determined based on the severity of illness and disease progression. 
  • Depending on the duration of expectant management, follow-up ultrasound examination for fetal growth evaluation and amniotic fluid volume estimation should also be performed.

Prenatal care:

  • Control of maternal blood pressure. Antihypertensive medications should be considered if systolic blood pressure remains persistently >160 mm Hg, or if diastolic blood pressure persists >110 mm Hg. The target range should be a systolic blood pressure of 140-155 mm Hg and a diastolic blood pressure of 90-105 mm Hg.
  • Oral antihypertensive therapy commonly includes oral labetalol and calcium channel blockers. Labetalol can be initiated at 200 mg orally every 12 hours, and increase the dose up to 800 mg orally every 8-12 hours as needed (maximum total 2400 mg/d).  Oral long-acting nifedipine (up to 30-60 mg/d) can be used. 

Antepartum testing

  • Fetal assessment includes non-stress testing daily with biophysical profile if nonreactive NST result is encountered.  
  • Follow-up fetal growth evaluation and amniotic fluid volume estimation should also be performed. 
  • If fetal growth restriction is suspected, doppler blood flow studies should be considered. 


  • Patients who are not candidates for expectant management include women with eclampsia, pulmonary edema, disseminated intravascular coagulation, renal insufficiency, abruptio placentae, abnormal fetal testing, HELLP syndrome, or persistent symptoms of severe preeclampsia. 
  • Delivery should be considered for women declining or noncompliant to ongoing inpatient observation.
  • For women with severe preeclampsia before the limit of viability, expectant management has been associated with frequent maternal morbidity with minimal or no benefits to the newborn. 
  • Expectant management of a select group of women with severe preeclampsia occurring <34 weeks' gestation may improve newborn outcomes but requires careful in-hospital maternal and fetal surveillance.

Last Reaffirmed: Feb 1, 2013