Preeclampsia and Eclampsia (Toxemia of Pregnancy)

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
  • Most in younger women, primiparous women
  • Older (aged >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)[C] (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