Management and Treatment of Preeclampsia
Deliver at ≥37 Weeks Regardless of Severity
All women with preeclampsia at ≥37 weeks' gestation should undergo delivery after maternal stabilization, regardless of disease severity or fetal testing results. 1, 2, 3 This is the definitive treatment, as delivery of the fetus and placenta is the ultimate solution to preeclampsia. 4
Initial Assessment: Confirm Diagnosis and Classify Severity
Diagnostic Criteria
- Preeclampsia is defined as new-onset hypertension (BP ≥140/90 mmHg on repeat measurements) after 20 weeks' gestation. 1, 2
- Proteinuria is no longer mandatory for diagnosis, though when present it is confirmed by spot urine protein/creatinine ratio ≥30 mg/mmol, ≥300 mg/24 hours, or ≥1+ on dipstick. 1, 2
Identify Severe Features Immediately
Severe features requiring urgent intervention include: 1, 2
- Severe hypertension: BP ≥160/110 mmHg on two occasions at least 15 minutes apart
- Thrombocytopenia: platelets <100,000/μL
- Renal dysfunction: creatinine >1.1 mg/dL or doubling of baseline
- Elevated liver enzymes: AST/ALT ≥2× upper limit of normal
- Pulmonary edema
- Neurological symptoms: severe persistent headache, visual disturbances (scotomata, cortical blindness), or epigastric/right upper quadrant pain
Immediate Stabilization for Severe Hypertension
Blood Pressure Management
- Initiate urgent antihypertensive therapy within 15 minutes when BP ≥160/110 mmHg persists to prevent maternal cerebral hemorrhage and stroke. 1, 2
- Target BP: systolic 110-140 mmHg and diastolic 85 mmHg (or at minimum <160/105 mmHg). 1, 2
First-Line Antihypertensive Options
For severe hypertension (≥160/110 mmHg): 1, 2
- Oral nifedipine (preferred first-line)
- IV labetalol: 20 mg IV bolus, then 40 mg after 10 minutes, then 80 mg every 10 minutes (maximum cumulative dose 220 mg)
- IV hydralazine: 5-10 mg IV every 20 minutes as needed
For non-severe hypertension (140-159/90-109 mmHg): 2
- Oral methyldopa, labetalol, oxprenolol, or nifedipine
Critical Contraindications
- Never use ACE inhibitors, ARBs, or direct renin inhibitors due to severe fetotoxicity causing renal dysgenesis. 1
- Avoid diuretics as they further reduce plasma volume, which is already compromised in preeclampsia and can worsen uteroplacental perfusion. 1, 2
Seizure Prophylaxis with Magnesium Sulfate
Indications for Magnesium Sulfate
Administer magnesium sulfate immediately to: 1, 2, 5
- All patients with severe preeclampsia (any severe feature present)
- Patients with proteinuria plus severe hypertension (≥160/110 mmHg)
- Any patient with neurological symptoms (headache, visual changes, epigastric pain)
Dosing Protocol
- Loading dose: 4-5 g IV over 5 minutes (diluted in 250 mL of 5% dextrose or 0.9% normal saline) 2, 5
- Maintenance: 1-2 g/hour continuous IV infusion 2, 5
- Alternative regimen: After initial IV dose of 4 g, give 4-5 g IM into alternate buttocks every 4 hours as needed 5
- Target serum magnesium level: 6 mg/100 mL is optimal for seizure control 5
Critical Safety Considerations
- Do not exceed 30-40 g total daily dose (or 20 g/48 hours in severe renal insufficiency). 5
- Do not continue beyond 5-7 days as prolonged use can cause fetal abnormalities. 5
- Monitor patellar reflexes and respiratory function before each dose. 5
Comprehensive Laboratory and Fetal Assessment
Initial Laboratory Workup
Obtain baseline tests including: 1, 2
- Complete blood count with focus on hemoglobin and platelet count
- Comprehensive metabolic panel: liver transaminases (AST/ALT), creatinine, uric acid
- Spot urine protein/creatinine ratio
Ongoing Monitoring Protocol
- Repeat laboratory tests at least twice weekly or more frequently if clinical deterioration occurs. 1, 2
- Monitor BP continuously or every 4 hours while awake. 1
- Perform clinical assessments including deep tendon reflexes and clonus evaluation. 1
Fetal Surveillance
- Initiate serial ultrasound assessments for fetal biometry, amniotic fluid volume, and umbilical artery Doppler to monitor for intrauterine growth restriction. 1
- Perform electronic fetal heart rate monitoring to assess fetal well-being. 1, 3
- Biophysical profile including fetal breathing movements, body movements, and tone. 3
Delivery Timing: Gestational Age-Based Algorithm
≥37 Weeks' Gestation
- Deliver immediately after maternal stabilization regardless of severity. 1, 2, 3
- Do not delay delivery based on non-reactive NST—delivery is indicated regardless of fetal testing results. 2, 3
34-37 Weeks' Gestation
- Without severe features: Expectant management with close monitoring is appropriate. 1
- With severe features: Deliver after maternal stabilization. 1, 2
<34 Weeks' Gestation
- Expectant management may be considered in select cases with stable maternal condition and reassuring fetal status, in facilities with appropriate maternal and neonatal intensive care capabilities. 1, 6
- Most studies report 7-10 days of pregnancy prolongation with expectant management. 6
Absolute Indications for Immediate Delivery (Any Gestational Age)
Deliver immediately regardless of gestational age if any of the following develop: 1, 2
- Repeated episodes of severe hypertension (≥160/110 mmHg) despite treatment with ≥3 classes of antihypertensives in appropriate doses
- Progressive thrombocytopenia (declining platelet counts on serial measurements)
- Progressively abnormal liver or renal function tests (worsening trends, not static elevations)
- Pulmonary edema
- Severe intractable headache, repeated visual scotomata, or eclamptic seizures
- Non-reassuring fetal status on continuous monitoring
- Placental abruption
- Maternal oxygen saturation deterioration (<90%)
Special Considerations: HELLP Syndrome
Recognition and Management
- HELLP syndrome is defined by hemolysis, elevated liver enzymes (AST/ALT ≥2× upper limit), and low platelets (<100,000/μL). 2
- Epigastric or right upper quadrant pain is a hallmark symptom. 2
- HELLP syndrome is part of the preeclampsia spectrum and should be managed as severe preeclampsia with all features addressed. 2
- Maternal mortality rate is 3.4% in HELLP syndrome. 2
- Monitor glucose intraoperatively as severe hypoglycemia can occur. 2
Pulmonary Edema Management
- Drug of choice is IV nitroglycerin (glycerol trinitrate) starting at 5 mcg/min, gradually increased every 3-5 minutes to maximum 100 mcg/min. 2
- Plasma volume expansion is NOT recommended routinely. 2
Setting of Care Requirements
Management must occur in a hospital with: 1, 2
- Appropriate obstetrical care facilities
- Maternal intensive care capabilities
- Neonatal intensive care unit (NICU) for extremely premature infants
- Coordination with maternal-fetal medicine specialists, neonatology, and anesthesiology teams
Postpartum Management
Blood Pressure Monitoring
- Monitor BP and clinical condition at least every 4 hours while awake. 2
- Continue antihypertensives administered antenatally. 2
Analgesia Considerations
- Avoid NSAIDs for postpartum analgesia unless other analgesics are not working, especially if renal disease or placental abruption are present, as NSAIDs can worsen renal function in preeclampsia. 1, 2
Follow-Up
- Review all women at 3 months postpartum to ensure BP, urinalysis, and laboratory abnormalities have normalized. 2
- Initiate appropriate referral for further investigations if proteinuria or hypertension persists. 2
- Women with preeclampsia have significant long-term cardiovascular risks requiring annual medical review life-long. 2
Critical Pitfalls to Avoid
- Do not underestimate disease severity based on "mild" classification—all preeclampsia can rapidly progress to life-threatening emergencies. 2, 3
- Blood pressure level alone is not a reliable indicator of disease severity—serious organ dysfunction can develop at relatively mild BP elevations. 1, 2
- Do not use serum uric acid level or degree of proteinuria as indications for delivery. 1, 2
- Do not delay delivery at ≥37 weeks based on non-reactive NST—delivery is indicated regardless of fetal testing results. 2, 3
- Do not reduce antihypertensives if diastolic BP falls <80 mmHg. 2
- Consider alternative diagnoses if preeclampsia presents before 20 weeks, as it rarely occurs this early except with trophoblast diseases such as hydatidiform mole. 1