Preeclampsia

Background

  1. Preeclampsia and eclampsia are diagnosed after 20wks gestation and <4wk post-partum
    1. May occur sooner w/ gestational trophoblastic disease
  2. Defined as SBP>140 or DBP>90 in previously normotensive pt AND proteinuria >0.3gm in 24h or persistent proteinuria > 1+ on dipstick
  3. Only 10% of cases occur prior to 34wk

Risk Factors

  • Past history of preeclampsia
  • First pregnancy
  • Family history of preeclampsia
  • Preexisting medical conditions:
    • Pregestational diabetes
    • Blood pressure ≥130/80 mm Hg at the first prenatal visit
    • Antiphospholipid antibodies
    • Body mass index ≥26.1
    • Chronic kidney disease
    • Twin pregnancies
    • Advanced maternal age

Work-Up

  • CBC
  • Chemistry
    • Elevated Cr suggests severe disease
  • LFT
    • AST/ALT elevation suggests severe disease
  • LDH
    • Elevation suggests microangiopathic hemolysis
  • Uric acid level
    • Often elevated in preeclampsia
  • UA
    • Proteinuria

Diagnosis

  • Mild preeclampsia:
    • SBP > 140 or DBP > 90
    • Proteinuria > 0.3 g/24 hrs or > 1+ on urine dipstick
  • Severe preeclampsia suggested by any of the following:
    • SBP >160 or DBP>110
    • Neurologic sequelae
    • Pulmonary edema
    • GI involvement
      • Epigastric or RUQ pain
      • LFT abnormalities (> 2x normal)
    • Thrombocytopenia < 100,000 plt/mm^3
    • Impaired fetal growth
    • Oliguria (<500 mL in 24hr)
    • Proteinuria of 5 gm in 24hr OR 3+ on two random urine samples collected 4hr apart
      • Lack of proteinuria is not rule-out!

In 2013, ACOG has decided to remove proteinuria from the definition of preeclampsia

ACOG Diagnostic Criteria[1]

Elevated Blood Pressure

  • Elevated blood pressure after 20 weeks of gestation in a previously normotensive patient, defined as EITHER:
    • SBP ≥160 mmHg or diastolic ≥110 mmHg on repeat blood pressure checks over several minutes, OR
    • SBP ≥140 mmHg or diastolic ≥90 mmHg on two occasions at least four hours apart

Proteinuria Criteria

  • Elevated blood pressure (see above), AND
  • Proteinuria:
    • Dipstick 1+ (if a quantitative measurement is unavailable), OR
    • Proteinuria ≥0.3 grams in a 24-hour urine specimen or protein (mg/dL)/creatinine (mg/dL) ratio ≥0.3

Non-Proteinuria Criteria

  • Elevated blood pressure (see above), AND
  • Any one of the following:
    • Platelet count <100,000/microliter
    • Serum creatinine >1.1 mg/dL or doubling of serum creatinine in the absence of other renal disease
    • Liver transaminases at least twice the normal concentrations
    • Pulmonary edema
    • Cerebral or visual symptoms

Differential Diagnosis

3rd Trimester/Postpartum Emergencies

Hypertension

Treatment

  • Only definitive treatment is delivery
    • Mild preeclampsia - induction or C-section if > 37 wks; consider close monitoring if 34-37 wks
    • Severe Preeclampsia - induction or C-section independent of gestational age

BP Control

  • Lower to Sys 130-150, dia 80-100
    • Labetalol
      • Option 1: Initial 20mg; then doses of 20-80mg q10min to total of 300mg
      • Option 2: Initial 20mg; then IV infusion of 1-2mg/min
    • Hydralazine
      • 5mg IV over 1-2min; repeat bolus of 5-10mg q20min PRN to total of 30mg

Prevention

  • The USPSTF recommends the use of low-dose aspirin (81 mg/d) as preventive medication after 12 weeks of gestation in women who are at high risk for preeclampsia. ( B recommendation)[2]
  • Magnesium: Load 4-6g IV over 15min followed by 2-3g per hr in coordination with admission by OBGYN
    • Observe for loss of reflexes, respiratory depression

Disposition

  • Consult w/ OB/GYN regarding d/c versus admission
    • Some cases of mild preeclampsia may be candidates for outpatient therapy
      • Close follow up and return precautions is key
      • Repeat lab tests 1-2x per week (platelet count, creatinine, AST)

See Also

Source

  • EBM, Volume 12, Number 8, Aug 2010. Postpartum Emergencies
  1. Hypertension in pregnancy: Report of the American College of Obstetricians and Gynecologists' Task Force on Hypertension in Pregnancy. Obstet Gynecol 2013; 122:1122.
  2. http://annals.org/article.aspx?articleid=1902275