Description

• Preeclampsia:
  • A disorder of pregnancy occurring after 20 weeks’ gestation characterized by new-onset hypertension (HTN), new-onset proteinuria, ± impaired organ function:
    • May progress from mild to life-threatening in hours to days
    • Reversible by delivery
• Eclampsia:
  • New-onset grand mal seizure activity with no history of underlying neurologic disease
• Most postpartum cases of preeclampsia and eclampsia occur within 48 hours of delivery but can occur up to 4 weeks postpartum.
• System(s) affected: cardiovascular, renal, reproductive, fetoplacental, CNS, hepatic, pulmonary
• Synonym(s): toxemia of pregnancy

Epidemiology

Incidence
Preeclampsia occurs in 5–8% of all pregnancies.

Prevalence

• Predominant age
  • Most in younger women, primiparous women
  • Older (>40 years) patients with preeclampsia have 4 times the incidence of seizures compared with patients in their 20s.
• Eclampsia occurs:
  • 1.6 to 10 out of 10,000 deliveries in developed countries
  • 6 to 157 out of 10,000 deliveries in developing countries
• 40% of eclamptic seizures occur before delivery; 16% occur >48 hours after delivery.
• Eclampsia is a main cause of perinatal mortality and morbidity (2–8% of all pregnancies).

Etiology and Pathophysiology

• Cause of preeclampsia is becoming clearer.
  • Abnormal placental implantation
  • Angiogenic factors
  • Genetic predisposition
  • Immunologic phenomena
  • Vascular endothelial damage and oxidative stress
• Systemic derangements in eclampsia include the following:
  • Cardiovascular: generalized vasospasm
  • Hematologic: decreased plasma volume, increased blood viscosity, hemoconcentration, coagulopathy
  • Renal: decreased glomerular filtration rate
  • Hepatic: periportal necrosis, hepatocellular damage, subcapsular hematoma
  • CNS: cerebral vasospasm and ischemia, cerebral edema, cerebral hemorrhage

Genetics
2 to 4 times increased risk in pregnant women with family history of preeclampsia

Risk Factors

• Nulliparity
• Age >40 years
• Family history of preeclampsia
• High body mass index
• Diabetes
• Chronic HTN
• Chronic renal disease
• Multifetal pregnancy
• Previous pregnancy with preeclampsia
• Systemic lupus erythematosus
• In vitro fertilization

General Prevention

• Adequate prenatal care
• Inadequate prenatal care results in 7 times increase in mortality.
• Good control of preexisting HTN
• Low-dose aspirin (ASA) (60 to 80 mg):
  • ASA started early after 12 weeks’ gestational age [GA]) may lower the risk of developing preeclampsia and the rate of preterm delivery and neonatal death in moderate- to high-risk patients (1)[B] (see “Risk Factors” as mentioned earlier).
• Low-dose calcium supplementation has been shown to reduce the risk and severity of preeclampsia in calcium-deficient populations.
• Some evidence suggests vitamin C (1,000 mg/day) and vitamin E (400 IU/day) may reduce the risk for preeclampsia, but recent guidelines recommend against their use.

Commonly Associated Conditions

Abruptio placentae, placental insufficiency, fetal growth restriction, preterm delivery, fetal demise maternal seizures (eclampsia), maternal pulmonary edema, maternal liver/kidney failure, or maternal death