Hypertension in Pregnancy

For more information, see ACOG Practice Bulletin No. 202: Gestational Hypertension and Preeclampsia

Maternal Hypertension.jpg

Chronic Hypertension in Pregnancy

36 y/o G1P0 at < 20 WGA with h/o HTN and pregestational DM presents for prenatal care. BP ≥ 140/90 on two occasions > 4 hours apart. Patient previously on an ACE inhibitor and atenolol; medications discontinued prior to pregnancy due to reduce IUGR risk. Family history includes preeclampsia. BMI > 30 kg/m^2. Dating ultrasound shows multiple gestation.

  • CBC, CMP, urine protein/creatinine all WNL

  • Monitor for IUGR: Refer for growth scan after 20 WGA if fundal height is 3 cm less than gestational age

  • Continue thiazide diuretic started before pregnancy

  • BP ≥ 150/100: Start one of the following medications and add a second agent if necessary

    • Nifedipine ER 30 mg qd (MDD 120 mg/day)

    • Labetalol 100 mg BID (MDD 200 mg BID)

    • Methyldopa 250 mg BID (MDD 250 mg BID when combined with other antihypertensives)

Notes

  • Definition: BP ≥ 140/90 on two occasions > 4 hours apart before 20 WGA

  • Risk factors include advanced maternal age (≥ 35 y/o at delivery), multiple gestation, chronic HTN, pregestational DM, family h/o preeclampsia, BMI > 30 kg/m^2

  • Chronic HTN is also diagnosed if elevated blood pressures persist past 12 weeks postpartum

Gestational Hypertension

Patient with no h/o HTN before 20 WGA presents for prenatal care. BP ≥ 140/90 on two occasions > 4 hours apart.

  • CBC, CMP, urine protein/creatinine all within normal limits

  • BP ≥ 150/100: Start one of the following medications and add a second agent if necessary

    • Nifedipine ER 30 mg qd (MDD 120 mg/day)

    • Labetalol 100 mg BID (MDD 200 mg BID)

    • Methyldopa 250 mg BID (MDD 250 mg BID when combined with other antihypertensives)

  • Perform in-office BP and non-stress test once weekly until delivery

  • Delivery

    • Induce if > 34 WGA with 1 or more of the following risk factors: Rupture of membranes, fetal size < 5th percentile on ultrasound, suspected abruptio placenta

    • Induce at 37 WGA in the absence of additional risk factors

 

Preeclampsia without Severe Features

45 y/o G1P0 twin gestation at > 20 WGA with h/o DM and renal disease presents with BP ≥ 140/90 on two occasions 4 hours apart. Denies headache, changes in vision. Reports preeclampsia during a previous pregnancy and h/o preeclampsia in a 1st degree relative. Elevated BMI, lungs clear to auscultation bilaterally, and no RUQ or epigastric pain on exam.

  • Labs

    • Spot urine protein/urine creatinine ratio > 0.3

    • Platelets > 100,000/mL, serum creatinine < 1.1 mg/dL, and liver transaminase levels less than 2 times the upper limit of normal

    • Consider antiphospholipid antibody assay if concern for autoimmune disease

    • Obtain weekly CBC, CMP

  • Imaging

    • Twice weekly in-office blood pressure and NST until delivery

    • Once weekly amniotic fluid index until delivery

    • Fetal growth ultrasonography every 3 weeks until delivery to monitor for IUGR

  • Start magnesium prophylaxis if severe features develop, i.e. headache that does not resolve with Tylenol, vision changes (blurring/flashing/scotoma), platelets < 100,000/mL, serum Cr > 1.1, AST or ALT > 2x upper limit of normal

  • Delivery

    • > 34 WGA with ≥ 1 risk factors (ROM, abnormal MFM results, size <5th percentile on U/S, suspected abruptio placenta): Start induction

    • No risk factors: Induce at 37 WGA

  • Postpartum

    • Observe for 72 hours

    • Follow-up appointment within 10 days of discharge

    • Patient instructed to call office if she develops H/A, changes in vision, N/V, CP, SOB, RUQ pain, edema

    • Aspirin 162 mg qd starting at 12 WGA during future pregnancies

Notes

  • Preeclampsia definition: Systolic BP ≥ 140 or diastolic BP ≥ 90 on two occasions 4 hours apart AND a spot urine protein/urine creatinine ratio > 0.3

  • Risk factors for preeclampsia include maternal age > 40 y/o, nulliparity, multiple gestation, preexisting diabetes mellitus, renal disease, history of preeclampsia, preeclampsia in a 1st degree relative, elevated BMI, and presence of phospholipid antibodies

 

Preeclampsia with Severe Features

45 y/o G1P0 twin gestation at > 20 WGA with h/o DM and renal disease presents with BP ≥ 160/110 on two occasions 15 minutes apart. Reports blurred vision with aberrations/scotoma, H/A not responding to analgesia. Crackles on lung exam concerning for pulmonary edema. Upper and lower extremity edema noted, 3+ patellar reflexes b/l.

  • Labs

    • Platelets < 100,000/microliter, serum creatinine > 1.1 mg/dL, and AST and ALT levels > 2 times the upper limit of normal

    • Obtain urine protein and urine creatinine

    • Consider obtaining serum LDH and uric acid levels

  • Admit to inpatient for monitoring

  • BP control

    • No bradycardia: Labetalol 20 mg IV <10min> 40 mg <10min> 80 mg <10min> hydralazine 10 mg IV <20min> emergency consult

    • Bradycardia present: Hydralazine 10mg IV <20 min> 10 mg <20min> labetalol 20 mg IV <10 min> labetalol 40 mg IV and an emergency consult

  • Seizure prophylaxis

    • No h/o myasthenia gravis: Magnesium 6g loading dose over 20 minutes

      • 2g/hr maintenance while patellar reflex present

      • Check magnesium level upon loss of patellar reflex, RR < 12, or UOP < 30cc/hr

      • Administer 1g Ca gluconate if concern for magnesium toxicity

    • H/o myasthenia gravis: Levetiracetam 500 mg IV BID

  • Management

    • IVF < 100mL/hr, oral intake < 25 mL per hour

    • Place Foley catheter and monitor UOP; goal = 30mL/hr

    • Delivery at 24-34 WGA

      • Immediate delivery in cases of severe/resistant HTN, eclampsia, pulmonary edema, abruption

      • Two doses IM betamethasone 12 mg q24h prior to delivery in cases of PLT < 100,000, transaminase 2x ULN, IUGR, severe oligohydramnios, umbilical artery reversed end-diastolic flow, worsening renal function.

    • Deliver at 37 WGA if no contraindications

    • Continue mag x 24 h postpartum; monitor for 72h postpartum

    • Nifedipine if HTN continues postpartum (max dose 30 mg qAM + 60 mg qhs)

  • Postpartum

    • Continue magnesium sulfate at 2g/hr for 24h

    • Observe for 72h

    • F/u appointment within 10 days of discharge

    • Pt instructed to call office if she develops H/A, changes in vision, N/V, CP, SOB, RUQ pain, edema

  • Aspirin 81mg qd starting at 12 WGA during future pregnancies

 

Eclampsia

Pt with h/o preeclampsia and no h/o trophoblastic disease presents with seizures at > 20 WGA. Seizures were preceded by H/A and visual changes. Convulsions lasted 60-90 sec and were followed by postictal state. No signs of injury on exam.

  • Pt placed on L side and intubation team notified

  • Administered 6g magnesium sulfate loading dose over 15 min

  • Continue magnesium at 2g/hr

  • Admit to L&D for continued observation

 

HELLP Syndrome

Pt with h/o preeclampsia with severe features presents with RUQ pain. Sudden onset of symptoms. Petechiae noted on exam.

  • CBC with platelet count < 50,000

  • Obtain CMP, fibrinogen, PT, PTT

  • Platelets < 20,000; administer platelets prior to attempted vaginal delivery and consider regional anesthesia if repeat platelets > 100,000

  • Continue magnesium until 24-48h postpartum