Blood Pressure Management in Pregnancy

1. See Also
   1. Gestational Hypertension Management
   2. Anti-Hypertensive Medications in Pregnancy
   3. Hypertensive Disorders of Pregnancy
   4. Delivery Indications in PIH
   5. Mild PIH Management
   6. Severe PIH Management
   7. PIH Blood Pressure Management
   8. PIH Seizure Prophylaxis
   9. HELLP Syndrome
2. Indications
   1. Blood Pressure exceeds 160/100 mmHg (Severe Preeclampsia)
3. Protocol: Initial program (Titrate to Diastolic Blood Pressure <100 mmHg)
   1. Labetolol (Normodyne)
      1. Safe and offers benefits over Hydralazine
         1. Lower Incidence of maternal Hypotension
         2. Lower Incidence of ceserean delivery
      2. Start: 20 mg IV bolus every 10-20 minutes prn
      3. Some recommend more aggressive management
         1. Start at Labetolol 20 mg IV for first dose as above
         2. If insufficient effect after 10 min: 40 mg IV
         3. If insufficient effect after 10 min: 80 mg IV
         4. If insufficient effect after 10 min: 80 mg IV
         5. Switch to other drug if no effect with 220 mg total
      4. Oral dosing is safe and effective
         1. May be dosed up to a very high maximum (2400 mg/day)
      5. Contraindications
         1. Avoid in Asthma
         2. Avoid in Congestive Heart Failure
   2. Nifedipine XL (Procardia XL)
      1. More rapid control of Hypertension than Labetolol
      2. Avoid short-acting Nifedipine as well as other Calcium Channel Blockers
      3. Could it block calcium as Magnesium Sulfate antidote?
      4. Start: 10 mg PO every 20-30 minutes prn
   3. Hydralazine (Apresazide)
      1. Was considered drug of choice due to 30 years of PIH use
         1. Now considered third line (after Labetolol and Nifedipine) due to adverse effects
      2. Adverse effects
         1. Fetal Tachycardia
         2. Maternal Headache or Palpitations
      3. Start: 5 mg IV or 10 mg IM every 20 minutes prn
      4. Maintenance: 5 mg IV or 10 mg IM every 3 hours prn
      5. Switch to another agent if no success
         1. After 20 mg IV total or
         2. After 30 mg IM total
4. Management: Maintanence medications (titrate to keep Diastolic BP <100)
   1. Methyldopa 250-500 mg PO bid-qid
   2. Atenolol 50-100 mg PO qd
   3. Metoprolol 25-100 mg PO bid
   4. Labetalol 100-400 mg PO bid
   5. Hydralazine 10-50 mg PO qid
   6. Nifedipine
5. Precautions
   1. Antihypertensives 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
      2. Aggressive lowering of Blood Pressure may result in adverse fetal outcomes
      3. Severe chronic Hypertension (consistently >150-180/100-110) should be treated
      4. (2001) Obstet Gynecol 98(1 suppl): 177-85
   2. Avoid contraindicated antihypertensives
      1. Avoid ACE Inhibitors and ARBs (due to neonatal Renal Failure, Teratogenic, IUGR)
      2. Avoid Atenolol (due to IUGR)
      3. Avoid Thiazide Diuretics (maternal fluid depletion)
6. References
   1. (2000) Am J Obstet Gynecol 183(1):S1-22
   2. Sibai (1996) N Engl J Med 335:257-65