Almost 10% of pregnant women have hypertension:
Pre-existing: 1%, Gestational hypertension: 5-6%, Preeclampsia: 2%
Chronic hypertension (in pregnancy): systolic BP 140+ or diastolic BP 90+ began before pregnancy – severe: if systolic >160 or diastolic >110
-diagnosed before pregnancy week 20 (or if persists >12 weeks after delivery)
-increased risk of pregnancy complications: placental abruption, preeclampsia, low birth weight, c- section, premie, fetal demise
-1st line treatment = labetalol: starting dose 100 mg PO twice daily
– goal is NOT to make BP normal in acute setting, just to reach target of 140-150/90-100
Gestational hypertension: present only AFTER pregnancy week 20 or in immediate postpartum period. NO proteinuria.
Safe treatment options for severe chronic or gestational hypertension: labetalol, nifedipine, hydralazine
– of note: all hypertensive drugs cross the placenta
– do NOT use ACEIs or ARBs: teratogenic to fetal lungs, kidneys, scalp
Hypertensive emergency: severe HTN (usually systolic >180 or diastolic >120 AND end organ damage Management options:
– labetalol 20 mg IV
– nifedipine 10-30 mg IV or IM
– hydralazine 5 mg IV or IM
Preeclamspia: new HTN AFTER 20 weeks gestation + proteinuria or organ dysfunction Important: can occur even up to 6 weeks postpartum
Let’s break that down into its parts:
- HTN: systolic BP 140+ or diastolic 90+, no prior HTN, >20 weeks gestation
o Preeclampsia w/ features of severe disease (formerly called severe preeclampsia) = systolic 160 + or diastolic 110+
o Take BP measurement x2 15 min. apart to confirm - Proteinuria: dipstick with 1+ or more (this is usually how we’d see it in the ED) o Also 300 mg or more in 24h or protein:Cr ratio 0.3 mg/dl or more
- Organ dysfunction can manifest as:
o neuro: cerebral dysfunction, vision changes
o liver: LFTs elevated 2x normal or persistent RUQ/epigastric pain o renal: Cr >1.1 or double of baseline Cr
o lungs: pulmonary edema
o thrombocytopenia (<100,000)
Cause of preeclamspia is unknown. Involves placenta vascular changes + thrombosis > placenta ischemia + infarctions
Preeclampsia is associated with pregnancy complications: IUGR, premature labor, low birth weight, placental abruption, future risk of maternal cardiovascular disease
Risk factors: preeclampsia in 1st pregnancy, mom age >40, HTN, DM, renal disease, multiple gestation
Eclampsia = preeclampsia + new seizure(s)
– can occur up to 4 weeks postpartum
– consider in any patient 20 weeks gestation to 4 weeks postpartum who is encephalopathic – occasionally can occur without HTN or proteinuria
Management:
Similar for severe preeclamspia & eclampsia
– Antihypertensive med + IV mag sulfate
AntiHTN meds help prevent sequelae of elevated BP including stroke. They do not prevent eclampsia.
Consult obgyn, emergently for eclampsia to facilitate delivery
if 34 weeks+, delivery indicated for severe preeclampsia
Only definitive management = delivery
Dispo: Admit. *Some mild preeclampsia can be discharged with obgyn consult on board as long as close outpatient mgmt available for repeat clinical + lab evals & fetal monitoring
Anti-HTN meds:
- Labetalol: o IV push: 20 mg IV then 40-80 mg IV q10min. prn, max dose 300 mg o IV infusion: 1-2 mg/min titrated
o Onset=5min.
o Avoid in patients with asthma or HR <50 bpm - Hydralazine: 5 mg IV or 10 mg IM, repeat q20 min. prn, max 20 mg IV or 30 mg IM o Onset = 20 min. o Labetalol is preferred over hydralazine: less hypotension + reflex tachycardia
- Nifedipine: 10 mg PO, repeat in 30 min. prn o Onset = 10-20 min. Mag sulfate: 4-6g 10% solution IV over 15-20 minutes then 1-2 g/hour continuous infusion (for at least 24 hours)
– Mag is renally excreted: for renal insufficiency reduce IV bolus to 2g + get serum mag level before dose increase
Monitor for signs of hypermagnesemia: flushing, diaphoresis, hypothermia, hypotension, flaccid paralysis, respiratory depression
Sources:
Tintinalli’s: Chapter 100: Maternal emergencies after 20 Weeks of pregnancy and in the Peripartum period
UpToDate: Treatment of hypertension in pregnant and postpartum patients; Chronic hypertension in pregnancy: prenatal and postpartum care; Preeclampsia: Antepartum management and timing of delivery
