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Preeclampsia and Eclampsia (Toxemia of Pregnancy)

BASICS

  • Preeclampsia: New-onset hypertension (HTN) after 20 weeks’ gestation plus proteinuria ± organ dysfunction.
  • Eclampsia: New-onset grand mal seizures in a woman with preeclampsia (no pre-existing neurologic disorder).
  • Most cases occur late in pregnancy or within 48 hours postpartum; can occur up to 6 weeks postpartum.

EPIDEMIOLOGY

  • Preeclampsia: 5–8% of pregnancies
  • Eclampsia: Main cause of perinatal mortality and morbidity (2–8% of pregnancies)
  • Most common in: Primiparous and younger women; risk increases with age >40

ETIOLOGY & PATHOPHYSIOLOGY

  • Genetic predisposition & abnormal placentation
  • Angiogenic factors, vascular endothelial damage, oxidative stress
  • Systemic effects: Vasospasm, hemoconcentration, decreased GFR, hepatic injury, CNS vasospasm/ischemia

RISK FACTORS

  • Nulliparity
  • Age >40 years
  • Family history of preeclampsia
  • Pre-existing HTN, diabetes, renal disease, obesity, SLE
  • Multiple gestation, prior preeclampsia, IVF

GENERAL PREVENTION

  • Prenatal care & BP control
  • Low-dose aspirin (60–80 mg) after 12 weeks GA in moderate/high-risk women
  • Calcium supplementation in deficient populations

COMMONLY ASSOCIATED CONDITIONS

  • Abruptio placentae
  • Fetal growth restriction, preterm delivery, fetal demise
  • Maternal complications: seizures, pulmonary edema, liver/kidney failure, maternal death

DIAGNOSIS

Preeclampsia Diagnosis

  • BP ≥140/90 mm Hg (2x, 4 hrs apart after 20 weeks)
  • AND proteinuria (>300 mg/24 hr, protein/creatinine ≥0.3, or dipstick ≥2+)
  • OR (if no proteinuria):
  • Platelets <100,000/µL
  • Transaminases >2x normal ± RUQ pain
  • Creatinine >1.1 mg/dL or doubling
  • Pulmonary edema
  • Headache or visual symptoms

Preeclampsia with Severe Features

  • BP ≥160/110 mm Hg (after 20 weeks) AND any severe feature above

Eclampsia Diagnosis

  • New-onset tonic-clonic, focal, or multifocal seizures (no history of epilepsy)

HISTORY & EXAM

  • May be asymptomatic
  • Rapid excessive weight gain (>2.3 kg/week)
  • Severe: RUQ/epigastric pain, headache, altered mental status, visual symptoms
  • Seizures (single or recurrent)

Physical Exam - BP as above - Headache, visual changes, RUQ pain may precede seizures

DIFFERENTIAL DIAGNOSIS

  • Chronic/gestational HTN
  • Chronic HTN with superimposed preeclampsia
  • Seizure disorders (epilepsy, tumors, meningitis, ruptured aneurysm)
  • Gestational HTN (no proteinuria/organ dysfunction)

DIAGNOSTIC TESTS

  • Urinalysis for protein at each prenatal visit
  • CBC, creatinine, transaminases, LDH, uric acid
  • 24h urine or spot protein/creatinine
  • Fetal monitoring: kick counts, NST, BPP, US for growth/amniotic fluid
  • HELLP suspicion: look for DIC, thrombocytopenia, liver/renal failure

TREATMENT

General Principles

  • Balance timing of delivery with maternal/fetal risks
  • Definitive treatment: DELIVERY
  • Preeclampsia (any severity) at ≥37 weeks: Recommend delivery

Preeclampsia without Severe Features

  • Possible outpatient management if stable
  • Daily BP, weekly labs
  • Fetal: kick counts, NST/BPP/US
  • Deliver at 37 weeks

Preeclampsia with Severe Features

  • Admit for inpatient care
  • Daily labs, continuous fetal monitoring
  • Magnesium sulfate (MgSO₄) IV for seizure prophylaxis (continue 24h postpartum)
  • Antihypertensives to keep SBP <160 & DBP <110
  • Delivery at ≥34 weeks (immediate if maternal/fetal instability, HELLP, etc.)

Steroids for fetal lung maturity if <34 weeks

Eclampsia/Seizures

  • MgSO₄ IV bolus 4–6 g over 15–30 min, then 1–2 g/hr infusion
  • Additional MgSO₄ for recurrent convulsions; monitor reflexes, respiration, urine output

Antihypertensive Therapy

  • Start for BP ≥160/110 mm Hg within 30–60 min
  • IV Labetalol: 20 mg, repeat/titrate up to max 300 mg/day
  • IV Hydralazine: 5–10 mg, repeat/titrate
  • Oral Nifedipine: Immediate-release 10 mg, repeat in 20 min as needed

Second Line for Seizures

  • Diazepam, lorazepam, phenytoin, or phenobarbital if refractory

ONGOING CARE

  • History of preeclampsia = long-term CVD risk
  • Monitor BP postpartum (risk persists up to 6 weeks)
  • Avoid salt restriction; monitor fluid status
  • Counsel on recurrence risk in future pregnancies

PROGNOSIS

  • Recurrence up to 40% if preeclampsia before 30 weeks in nulliparas
  • 25% of eclamptics have HTN in future pregnancies
  • Higher future risk of essential HTN, mortality in multiparas

COMPLICATIONS

  • Maternal/fetal death
  • Neurologic deficits (usually transient)
  • Organ failure, abruptio placentae, DIC, HELLP syndrome

ICD-10 CODES

  • O14.90 Unspecified pre-eclampsia, unspecified trimester
  • O15.00 Eclampsia in pregnancy, unspecified trimester
  • O14.00 Mild to moderate pre-eclampsia, unspecified trimester

CLINICAL PEARLS

  • Management depends on severity & gestational age.
  • Magnesium sulfate is the DOC for severe preeclampsia/eclampsia.
  • Low-dose aspirin started late 1st trimester in high-risk women can prevent preeclampsia.
  • Continue maternal BP monitoring postpartum—risk persists after delivery.