A leading cause of maternal and fetal morbidity and mortality (eg, risk for stroke, placental abruption, disseminated intravascular coagulation).

• Pathophysiology

| Definition | • New-onset hypertension on 2 measurements ≥4 hr apart. (SBP ≥140 or DBP ≥90 mm Hg)at ≥20 weeks      AND • Proteinuria OR signs/symptoms of other end-organ damage | | --- | --- | | Severe features | • Severe-range hypertension (SBP ≥160 or DBP ≥110 mm Hg) • Platelets <100,000/mm3 • Creatinine >1.1 mg/dL or 2x normal • Elevated transaminases >2x upper limit of normal • Pulmonary edema • Vision or cerebral symptoms (eg, headache) | | Management | • <37 weeks & no severe features: expectant • ≥37 weeks (or ≥34 weeks with severe features): delivery • Severe-range blood pressure: IV labetalol, IV hydralazine,PO nifedipine • Seizure prophylaxis: magnesium sulfate |

| High risk | • Prior preeclampsia • Chronic kidney disease • Chronic hypertension • Diabetes mellitus • Multiple gestation (3x) • Autoimmune disease (eg SLE) • T1DM | | --- | --- | | Moderate risk | • Obesity • Advanced maternal age • Nulliparity • Long interpregnancy intervals (eg, >10 years) | | Prevention in high risk | • Low-dose aspirin at 12-28 weeks gestation (but optimally before 16 weeks) and continued daily until delivery. (Inhibits platelet aggregation and helps prevent placental ischemia) |

Twin gestation possibly due to greater placental mass→higher risk for placental hypoperfusion→placental ischemia.

Patients with type 1 diabetes mellitus (T1DM) are at risk for diabetic nephropathy (eg, proteinuria) and vascular disease (eg, hypertension), which are independent risk factors for preeclampsia

Preeclampsia is sub classified as either with or without severe features; this distinction is critical because patients with severe features have significantly greater morbidity (eg, eclampsia, abruptio placentae, fetal demise) and require different management

• Preeclampsia with severe features is diagnosed when ≥1 of the following is present:
  • Severe-range hypertension (SBP ≥160 or DBP ≥110 mm Hg)
  • Platelets <100,000/mm3
  • Creatinine >1.1 mg/dL or 2x normal
  • Elevated transaminases >2x upper limit of normal
  • Pulmonary edema
  • Headache (severe and/or persistent), visual changes (eg, scotomata, blurred vision)

Patients with preeclampsia are at increased risk of hemorrhagic and ischemic stroke due to acute elevations in cerebral perfusion pressure and vessel rupture (hemorrhagic), as well as preeclampsia-mediated vascular endothelial damage and microthrombi formation (ischemic).  To decrease this risk, preeclamptic patients with severe-range blood pressures require aggressive antihypertensive therapy (eg, labetalol, nifedipine) and magnesium sulfate, which helps prevent eclamptic seizures that can worsen stroke symptoms.

Most preeclamptic patients do not require imaging; however, in those with focal neurologic deficits, such as this patient with asymmetric motor deficits (strength right > left), CT scan of the head should be performed to evaluate for possible stroke and help guide management.

A complete molar pregnancy (hydatidiform mole) can present with preeclampsia, particularly at unusually early gestational ages (eg, <20 weeks gestation).

• Headaches are common in pregnancy, particularly in patients with a history of headaches outside of pregnancy.  Most cases of headache are benign, but women at ≥20 weeks gestation or with atypical headache symptoms require evaluation for preeclampsia.