Preeclampsia

Background

Definition

• Gestational hypertension is defined as hypertension developing on or after 20 weeks gestation
• Preeclampsia is gestational hypertension plus one of:
  • New proteinuria
  • One or more adverse conditions
    • CNS: headache, visual disturbance
    • Cardiorespiratory: chest pain, dyspnea, O2 sat <97%
    • Hematological: increased WBC, decreased platelets, increased INR/PTT
    • Renal: increased creatinine or uric acid
    • Hepatic: nausea/vomiting, RUQ pain, elevated AST/ALT/LDH/bilirubin, low albumin
    • Fetoplacental: IUGR, abnormal FHR, oligohydramnios, abnormal end-diastolic flow
  • One or more severe complications
    • CNS: eclampsia, neurological deficits, GCS<13, stroke/TIA
    • Cardiorespiratory: uncontrolled severe hypertension, O2 sat <90%, intubation, pulmonary edema, inotropes, ACS
    • Hematological: platelets <50k, need for any transfusions
    • Renal: AKI (Cr>150), new need for dialysis
    • Hepatic: INR >2, hepatic hematoma or rupture
    • Fetoplacental: abruption, stillbirth, reverse ductus venous A wave
• Severe preeclampsia is preeclampsia with one or more severe complications

Risk factors

• Highest-risk group are those with previous preeclampsia, antiphospholipid syndrome, and preexisting hypertension, renal disease, or diabetes mellitus
• Demographics: maternal age ≥40 years
• Family history: preeclampsia in mother or sister; early-onset cardiovascular disease
• Past medical and obstetrical history
  • Previous preeclampsia
  • Antiphospholipid syndrome
  • Preexisting hypertension, or DBP≥90 at intake
  • Preexisting renal disease, or proteinuria at intake
  • Preexisting diabetes mellitus
  • Lower maternal birthweight and/or preterm delivery
  • Heritable thrombophilias
  • Increase pre-pregnancy triglycerides
  • Non-smoking
  • Cocaine and methamphetamine use
  • Previous miscarriage at or before 10 weeks with the same partner
• Current pregnancy
  • First-trimester
    • Multiple pregnancy
    • Overweight or obesity
    • First ongoing pregnancy
    • New partner
    • Short duration of sexual relationship with current partner
    • Reproductive technologies
    • Inter-pregnancy interval ≥10 years
    • SBP ≥130 or DBP ≥80 at intake
    • Vaginal bleeding in early pregnancy
    • Gestational trophoblastic disease
    • Abnormal PAPP-A or free β-hCG
  • Second or third trimester
    • Gestational hypertension
    • Abnormal AFP, hCG, inhA, or E₃
    • Excessive weight gain in pregnancy
    • Infection during pregnancy
    • Abnormal uterine artyer Doppler
    • IUGR
    • Investigational laboratory markers

Clinical Manifestations

• Can present from 20 weeks of gestation to 6 weeks postpartum
• 5% of preeclampsia will progress to eclampsia

Management

• Monitoring
  • Monitor BP closely, at least q8h
  • Monitor liver enzymes q3-4d
• Seizure prevention
  • Give MgSO4 1g IV q1h until blood pressure controlled
• Blood pressure control
  • First-line: hydralazine 4-6mg IV slow push q15-30min prn hypertension
  • Second-line: nifedipine prn hypertension

Prevention

• Estimate risk based on risk factors (above)
• First-line:
  • Exercise
  • Folate-containing multivitamin
• If low calcium intake: calcium supplementation
• If at increased risk, add:
  • Low-dose aspirin, started between 11 and 14 weeks and continued until 36 weeks
  • Possible LMWH if high risk
  • L-arginine
  • Rest during third trimester