Hypertensive Crisis during Pregnancy Eric I Rosenberg MD

Hypertensive Crisis during Pregnancy Eric I. Rosenberg, MD, MSPH, FACP

“I stopped taking medicine when I got pregnant”

Hypertensive and Pregnant • 28 year old woman, G 4 P 2 • 29 week IUP • BP 233/125 mm. Hg • Admitted by High-Risk Obstetrical Service • Internist asked to advise on optimal antihypertensive regimen

History PMHx: Hypertension Meds: Preeclampsia x 2; 1 fetal demise Prenatal vitamins Allergies: Ø FH: Both parents hypertensive SH: Lives with 3 children. Smokes ½ ppd. Stopped Et. OH. No drug abuse. ROS: Remarkably negative.

Exam • P 88, BP 233/125 mm. Hg • BP 210/105 mm. Hg after 40 mg Labetalol • Normal exam – Alert, asymptomatic – No papilledema – Clear lungs – No S 3 or S 4 – No edema

Studies 134 103 9 4. 8 22 0. 8 11 12 34 66 ECG: LVH 205 Urine: no protein

What would you do next?

Key Issues for the Medical Consultant • How quickly should BP be normalized? • Which medications are most efficacious? • Which medications are safe in pregnancy? • Is this preeclampsia?

Severe Asymptomatic Hypertension • Consistent with chronically untreated and uncontrolled hypertension • Rapid correction associated with morbidity and no proven benefit – May induce cerebral or myocardial ischemia – Goal: < 160/100 mm. Hg over hours to days – Keep patient (and staff) calm

Hypertensive Disorders in Pregnancy • Preeclampsia – New onset hypertension (>140/90 mm. Hg) – Gestational age > 20 weeks – Proteinuria (>300 mg in 24 -hours) • Gestational Hypertension – New onset, IUP > 20 weeks, no proteinuria • Chronic Hypertension – Antedates pregnancy

Chronic BP >180/110 in 1 st Trimester is Strongly Associated with Fetal Demise • Preeclampsia: 50% • Placental abruption: 5 – 10% • Delivery < 37 weeks: 70% • Growth restriction: 35% Obstet Gynecol 2002 Aug; 100(2).

Keep BP <140/90 During Pregnancy • Mild chronic hypertension (>140/90) associated with up to 25% risk preeclampsia • Perform same evaluation as all other newly dx’d HTN patients – ECG – UA – Ophthalmologic exam – Creatinine • Close fetal surveillance by obstetrician

Key Issues for the Medical Consultant • How quickly should BP be normalized? • Which medications are most efficacious? • Which medications are safe in pregnancy? • Is this preeclampsia?

Do NOT use Immediate Release Nifedipine • No benefit • Not FDA approved for this purpose in any patient population • Associated with excessive reductions in BP

Contraindicated Antihypertensives in Pregnancy • Nitroprusside (D) • Cyanide poisoining if > 4 hours use • ACE-inhibitors (D) • Teratogenic • Angiotensin Receptor Blockers (D) • Teratogenic

Options for Acute Therapy • Labetalol (C) – Probably the safest option – No reports of teratogenicity • Hydralazine (C) – May be teratogenic – Associated with impaired uteroplacental perfusion – Possible maternal hepatoxicity during preeclampsia • Clonidine (C) – Case reports of birth defects if used throughout pregnancy – Should probably be avoided

Options for Chronic Therapy • Methyldopa (C) (Aldomet ®) – Commonly used, but no teratology studies – Mild; may not control BP adequately – Has sedative effects • Labetalol (C) – Most widely used beta-blocker – May preserve uteroplacental flow better than beta-blockers that don’t have alphablocking properties ACOG Chronic hypertension in pregnancy. July 2001.

Our Impression… “probable mild chronic hypertension now with poorly controlled gestational hypertension”

Recommendations • Labetalol 200 mg po twice daily • Clonidine 0. 1 to 0. 2 mg every 15 minutes for SBP > 200 mm. Hg • Monitor BP every 1 to 2 hours • Goal: 160/100 mm. Hg over several hours • Labetalol gtt if symptomatic

And a sad ending… • BP remained 150 – 200 / 83 – 119 mm. Hg • Patient left against advice the next day • Prescribed Labetalol 300 mg twice daily • Given appointment for f/u in 3 days • Presented 2 weeks later to clinic with no fetal heart tones, BP 190/92

Take-Home Points • This is an obstetrical area of expertise • But you may be asked for input on optimal control of newly discovered chronic hypertension during pregnancy • Educate patients on risks of all antihypertensive medications during pregnancy • Risks of uncontrolled hypertension outweigh risks of Category C medications