Preeclampsia and Eclampsia (Toxemia of Pregnancy)

Basics

Description

  • Preeclampsia: a disorder of pregnancy occurring after 20 weeks’ gestation characterized by new-onset hypertension (HTN), new-onset proteinuria, ± impaired organ function
  • 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 6 weeks postpartum.

Epidemiology

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

Prevalence

  • Predominant age
    • Mostly in younger women, primiparous women
    • Older (age >40 years) patients with preeclampsia have 4 times the incidence of seizures compared with patients in their 20s.
  • 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.
    • Genetic predisposition and abnormal placental implantation
    • Angiogenic factors
    • Vascular endothelial damage and oxidative stress
  • Systemic disorders 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
  • Maternal medical problems: diabetes, chronic HTN, chronic renal disease, obesity, systemic lupus erythematosus
  • Multiple gestation
  • Prior pregnancy with preeclampsia
  • In vitro fertilization

General Prevention

  • Adequate prenatal care
  • 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.

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

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