OB

Hypertension in Pregnancy

search

Hypertension in Pregnancy, Chronic Hypertension in Pregnancy, Gestational Hypertension

  • Definition
  1. Chronic Hypertension in Pregnancy
    1. Chronic Hypertension (140/90 mmHg) that extends into pregnancy without Preeclampsia
    2. Onset of Hypertension before 20 weeks gestation or persisting beyond 12 weeks after delivery
  2. Gestational Hypertension
    1. Hypertension in Pregnancy with onset beyond 20 weeks gestation and NO Proteinuria
  • Complications
  • Pregnancy Related
  1. Age 35 years or higher
  2. Antihypertensive needed for Blood Pressure control
  3. History of prior pregnancy complications
    1. Preeclampsia
    2. Untrauterine growth retardation
    3. Intrauterine Fetal Demise
  4. Comorbid conditions
    1. Diabetes Melllitus
    2. Systemic Lupus Erythematosus
    3. Chronic cardiopulmonary disease
    4. Renal disease
  5. Abnormal labs
    1. Serum Creatinine >1.0 mg/dl
    2. Proteinuria >300 mg/24 hours
    3. Phopholipid Antibody positive
  • Monitoring
  1. Initial evaluation (at time of diagnosis)
    1. Estimate Fetal Growth
    2. Estimate amniotic fluid index (AFI)
    3. Non-Stress Test (NST)
    4. Biophysical Profile (BPP) if NST not reactive
    5. Further evaluation if BPP <8
  2. Repeat Testing
    1. Ultrasound every 4 weeks starting at 28 weeks gestation
    2. Other testing as indicated for significant maternal status changes
  • Management
  1. See PIH Blood Pressure Management
  2. See Anti-Hypertensive Medications in Pregnancy
  3. Hypertension therapy during pregnancy does not reduce pregnancy complications
    1. See antihypertensives below
    2. Aspirin does not lower Preeclampsia risk
      1. Caritis (1998) N Engl J Med [PubMed]
    3. Low Sodium diet shows no benefit
    4. Minimizing weight gain shows no benefit
    5. Exercise restriction offers no benefit
  • Management
  • Anti-hypertensives
  1. See Blood Pressure Management in Pregnancy
  2. Goal: Lower Systolic Blood Pressure to <150/100 (much higher than non-pregnant goal)
  3. Anti-hypertensives are not indicated for mild to moderate Chronic Hypertension in Pregnancy
    1. Treatment of BP <150/100 does not reduce risk to fetus or prevent Preeclampsia
      1. Antihypertensives benefit mother only (these do not reduce pregnancy complications)
      2. van Dadelszen (2000) Lancet [PubMed]
    2. Aggressive lowering of Blood Pressure may result in adverse fetal outcomes (hypoperfusion)
    3. Severe chronic Hypertension (consistently >150-180/100-110) should be treated
    4. (2001) Obstet Gynecol 98(1 suppl): 177-85 [PubMed]
  4. Antihypertensive used in pregnancy
    1. Avoid contraindicated antihypertensives
      1. Avoid ACE Inhibitors and ARBs (despite mixed data in first trimester)
      2. Avoid Atenolol and Beta Blockers in general (other than Labetalol) due to IUGR risk
      3. Avoid Spironolactone, Eplerenone and Aliskiren
    2. Most commonly used antihypertensives in pregnancy
      1. Labetolol 200 mg PO bid (up to 1200 mg bid)
      2. Nifedipine XL 30 mg PO bid (up to 120 mg daily)
      3. Alpha Methyldopa 500 mg PO bid (up to 2 grams bid)
        1. Long safety record, but weak antihypertensive and less tolerated (Fatigue, Dizziness)
    3. Other antihypertensives used in pregnancy (less safety data)
      1. Felodipine 5 mg PO daily (up to 20 mg daily)
      2. Hydralazine 10 mg PO tid (up to 25 mg tid)
      3. Hydrochlorothiazide
        1. Not usually initiated in pregnancy due to volume depletion
        2. May be continued if on pre-pregnancy - consult with local expert opinion
  • Precautions
  • Chronic Hypertension in Pregnancy
  1. Observe for superimposed Preeclampsia on chronic Hypertension
  2. High index of suspicion if maked Blood Pressure increase or new onset Proteinuria
  • Precautions
  • Gestational Hypertension
  1. Preeclampsia will develop in 50% of those with Gestational Hypertension onset 24-35 weeks
    1. Barton (2001) Am J Obstet Gynecol 184(5): 979-83 [PubMed]
  2. Severe Gestational Hypertension is associated with worse outcomes than mild PIH
    1. Treat with same management protocol as Severe Preeclampsia
    2. Buchbinder (2002) Am J Obstet Gynecol 186:66-71 [PubMed]