Preeclampsia is a progressive, multi-organ hypertensive disorder of pregnancy occurring after 20 weeks' gestation, defined by new-onset hypertension (SBP ≥140 or DBP ≥90 mm Hg) with proteinuria or end-organ dysfunction. It complicates 2–8% of pregnancies and is a leading cause of maternal and perinatal morbidity and mortality worldwide. [1-3]
1. History
- Onset and timing: Gestational age at symptom onset (>20 weeks; earlier onset suggests molar pregnancy, TTP/HUS, or autoimmune disease) [1]
- Headache: New-onset, severe, persistent, unresponsive to acetaminophen [1]
- Visual changes: Blurred vision, scotomata, photophobia, diplopia [1][4]
- Epigastric/RUQ pain: Suggests hepatic involvement or capsule distension; may herald HELLP [1]
- Dyspnea/chest pain: Suggests pulmonary edema or cardiac involvement [3]
- Edema: Rapid-onset facial or hand swelling (though no longer a diagnostic criterion)
- Decreased fetal movement: Suggests fetal compromise
- Important negatives: Absence of seizure activity, no prior history of hypertension, no hematuria or flank pain
2. Alarm Features
- Severe-range BP: SBP ≥160 or DBP ≥110 mm Hg — treat within 30–60 minutes to prevent stroke [5-6]
- Eclamptic seizures: New-onset tonic-clonic seizures; 80% preceded by headache or visual symptoms [5]
- HELLP syndrome: Hemolysis, elevated liver enzymes, low platelets — rapid deterioration is characteristic; 15% present without hypertension or proteinuria [5]
- Pulmonary edema: Dyspnea, hypoxia, crackles [4]
- Oliguria or anuria: Suggests renal failure
- Placental abruption: Vaginal bleeding, abdominal pain, uterine tenderness
- Hepatic rupture/infarction: Rare but catastrophic, associated with early-onset disease [7]
- Presentation before 20 weeks: Consider TTP, HUS, molar pregnancy, renal disease, or SLE [1]
3. Medications
- Acute severe hypertension (first-line): [5-6][8]
- IV labetalol: 20 mg, then 40 mg, then 80 mg (max 300 mg)
- IV hydralazine: 5 mg bolus, then 5–10 mg (max 45 mg)
- PO immediate-release nifedipine: 10 mg (max 30 mg) — useful when no IV access
- Non-severe hypertension: Labetalol, nifedipine, or methyldopa PO [6][9]
- Seizure prophylaxis: Magnesium sulfate — 4–6 g IV loading dose, then 1–2 g/hr maintenance; recommended for preeclampsia with severe features (NNT = 36 for symptomatic patients, NNT = 129 for asymptomatic) [1][5]
- Pulmonary edema: IV nitroglycerin is preferred [6]
- Contraindicated: ACE inhibitors, ARBs, direct renin inhibitors — teratogenic [9]
- Caution: Concurrent magnesium sulfate and calcium channel blockers may cause synergistic hypotension [6]
- Prevention: Low-dose aspirin 81 mg/day starting after 12 weeks' gestation in high-risk patients [5][10]
4. Diet
- Calcium supplementation: May reduce preeclampsia risk, particularly in populations with low dietary calcium intake [2]
- Sodium: No strong evidence for strict restriction, but a heart-healthy diet is recommended postpartum [11]
- Hydration: Maintain adequate oral intake; avoid overhydration in the setting of oliguria or pulmonary edema
- Long-term: Heart-healthy diet (DASH-style) recommended postpartum for cardiovascular risk reduction [11]
5. Review of Systems
- Neurologic: Headache (character, severity, response to analgesics), visual changes, altered mental status, hyperreflexia, clonus
- GI: Nausea, vomiting, epigastric/RUQ pain
- Pulmonary: Dyspnea, orthopnea, cough (pulmonary edema)
- Renal: Decreased urine output, foamy urine
- Hematologic: Easy bruising, petechiae (thrombocytopenia)
- OB: Fetal movement, vaginal bleeding, contractions, leaking fluid
6. Collateral History and Family History
- Family history: Preeclampsia in mother or sister is a moderate risk factor for developing preeclampsia [10][12]
- Prior pregnancy history: Previous preeclampsia, HELLP, eclampsia, IUGR, stillbirth, or preterm delivery
- Partner history: New paternity is associated with increased risk (limited paternal antigen exposure)
- Social context: Access to prenatal care, ability to monitor BP at home, transportation for follow-up
7. Risk Factors
Per ACOG and USPSTF: [1][10][12]
- High-risk (any one → recommend aspirin prophylaxis):
- Prior preeclampsia
- Multifetal gestation
- Chronic hypertension
- Type 1 or 2 diabetes
- Renal disease
- Autoimmune disease (SLE, antiphospholipid syndrome)
- Moderate-risk (two or more → recommend aspirin prophylaxis):
- Nulliparity
- Obesity (BMI >30)
- Maternal age ≥35
- Family history of preeclampsia
- Black race (due to structural inequities, not biological propensity) [12]
- IVF conception
- Interpregnancy interval >10 years
- Prior adverse pregnancy outcome (low birth weight, SGA)
- Other: Obstructive sleep apnea, gestational diabetes, thrombophilia [1][4]
8. Differential Diagnosis
- Gestational hypertension: Hypertension without proteinuria or end-organ dysfunction; up to 50% progress to preeclampsia [5]
- Chronic hypertension with superimposed preeclampsia: Worsening BP control with new proteinuria or end-organ involvement [2]
- HELLP syndrome: May present without hypertension or proteinuria in 15% of cases [5]
- Thrombotic thrombocytopenic purpura (TTP): Microangiopathic hemolytic anemia, thrombocytopenia, neurologic symptoms, fever — consider if presentation <20 weeks [1]
- Hemolytic uremic syndrome (HUS): Predominant renal failure with microangiopathic hemolysis [1]
- Acute fatty liver of pregnancy: Nausea, vomiting, jaundice, hypoglycemia, coagulopathy — typically third trimester [5]
- Molar pregnancy: Can cause preeclampsia-like syndrome before 20 weeks [1]
- Pheochromocytoma: Paroxysmal hypertension, headache, diaphoresis
- SLE nephritis: Proteinuria, hypertension, may mimic preeclampsia
9. Past Medical History
- Prior preeclampsia, eclampsia, or HELLP (strongest predictor of recurrence)
- Chronic hypertension, diabetes (type 1, type 2, or gestational)
- Chronic kidney disease, autoimmune disease
- Thrombophilia or prior VTE
- Obesity, obstructive sleep apnea
- Prior cesarean delivery
- Surgical history relevant to delivery planning
10. Physical Exam
- Vital signs: BP in both arms (sitting, arm at heart level, appropriate cuff size — large cuff if arm circumference ≥33 cm); avoid left lateral position which falsely lowers readings [13]
- Neurologic: Mental status, deep tendon reflexes (hyperreflexia, clonus), visual fields, fundoscopy
- Cardiopulmonary: Crackles (pulmonary edema), S3 gallop, jugular venous distension
- Abdominal: RUQ/epigastric tenderness (hepatic capsule distension), fundal height, uterine tenderness (abruption)
- Extremities: Edema (facial, hands — more concerning than dependent edema), petechiae
- Fetal assessment: Fetal heart tones, fundal height
11. Lab Studies
Initial workup: [1][3][5]
- CBC with platelet count: Thrombocytopenia (<100,000 = severe feature)
- CMP: Creatinine (>1.1 mg/dL or doubling = severe feature), AST/ALT (>2× ULN = severe feature)
- LDH: Elevated in hemolysis (HELLP)
- Urine protein/creatinine ratio: ≥0.3 diagnostic; 24-hour urine ≥300 mg [1]
- Peripheral smear: Schistocytes if HELLP suspected
- Uric acid: Often elevated but not part of diagnostic criteria
Monitoring (after diagnosis): [1][3]
- Platelet count, creatinine, and liver enzymes at least twice weekly
- Weekly urine protein/creatinine for gestational hypertension
- Coagulation studies (PT/INR, fibrinogen) if HELLP or DIC suspected
Rule-out labs: Type and screen, fibrinogen, haptoglobin if hemolysis suspected
12. Imaging
- Obstetric ultrasound: Fetal growth assessment every 3–4 weeks; amniotic fluid volume weekly [5]
- Doppler velocimetry: Umbilical artery, middle cerebral artery, ductus venosus — repeated at least weekly [3]
- Chest X-ray: If pulmonary edema suspected [4]
- CT head: If atypical neurologic presentation, concern for intracranial hemorrhage, or posterior reversible encephalopathy syndrome (PRES)
- Liver imaging: If hepatic rupture or subcapsular hematoma suspected (ultrasound or CT)
- Echocardiography: If symptoms of heart failure, peripartum cardiomyopathy suspected [14]
13. Special Tests
- fullPIERS model: Externally validated risk prediction tool for adverse maternal outcomes — incorporates gestational age, chest pain/dyspnea, SpO₂, platelet count, creatinine, and aminotransferases [3]
- sFlt-1/PlGF ratio: Angiogenic biomarkers useful for predicting preeclampsia onset within 1–4 weeks in suspected cases; not yet standard in all settings [3]
- Non-stress test (NST): 1–2 times per week for fetal surveillance [5]
- Biophysical profile (BPP): Fetal well-being assessment
- Uterine artery Doppler: Elevated pulsatility index in early pregnancy may predict preeclampsia risk [15]
14. ECG
- Indications: Chronic hypertension, chest pain, dyspnea, suspected cardiomyopathy
- Findings to watch for: Left ventricular hypertrophy, ST changes (ischemia), arrhythmias
- Peripartum cardiomyopathy: Preeclampsia is a known risk factor — ECG may show sinus tachycardia, low voltage, or nonspecific ST-T changes [14][16]
15. Assessment
Severity stratification (per ACOG): [1]
Preeclampsia without severe features: BP 140–159/90–109 mm Hg with proteinuria, no end-organ dysfunction
Preeclampsia with severe features (any one of the following):
- SBP ≥160 or DBP ≥110 mm Hg
- Platelets <100,000
- Creatinine >1.1 mg/dL or doubling
- AST/ALT >2× ULN
- Pulmonary edema
- New-onset headache unresponsive to medication
- Visual disturbances
Complications: Eclampsia, HELLP, DIC, placental abruption, acute kidney injury, hepatic rupture, stroke, pulmonary edema, peripartum cardiomyopathy, fetal growth restriction, stillbirth [5][7]
Long-term: Preeclampsia significantly increases lifetime cardiovascular disease risk, including hypertension, ischemic heart disease, stroke, and heart failure [3][16]
16. Treatment Plan
Initial stabilization: [5-6][8]
- Treat severe hypertension within 30–60 minutes if BP ≥160/110 persists for 15 minutes
- IV labetalol, IV hydralazine, or PO nifedipine (see Medications above)
- Magnesium sulfate for seizure prophylaxis in severe features: 4–6 g IV load → 1–2 g/hr maintenance
- Monitor for magnesium toxicity: loss of DTRs (early), respiratory depression, cardiac arrest (severe) [5]
Gestational age–based management: [3][5]
The following table from the NEJM summarizes management by gestational age at diagnosis:
- <24 weeks: Extremely high maternal (≤70%) and fetal (50–82%) complication rates; delivery within 24–48 hours generally recommended
- 24–33⁶ weeks: Expectant management may be considered if no indications for timed birth; antenatal corticosteroids for fetal lung maturity; magnesium for fetal neuroprotection (<32 weeks)
- 34–36⁶ weeks: Delivery at 34 weeks for severe features; expectant care possible if stable
- ≥37 weeks: Delivery within 24–48 hours recommended
- Without severe features at any GA: Planned delivery at 37 weeks [5]
Antenatal corticosteroids: Betamethasone if <34 weeks (and consider for 34–36⁶ weeks per late-preterm steroid protocols) [3][5]
17. Disposition
- Admit: All patients with preeclampsia with severe features require inpatient management from diagnosis until delivery [5]
- Outpatient management may be considered: Preeclampsia without severe features or gestational hypertension, with close surveillance (BP checks 1–2×/week, weekly labs, fetal testing) [1]
- Tertiary care transfer: HELLP syndrome, eclampsia, or preeclampsia <34 weeks requiring expectant management [5]
- OB consultation: All cases of preeclampsia; MFM consultation for preterm preeclampsia or complex cases
- Anesthesia consultation: Early in admission for patients with severe features (epidural planning, airway assessment)
18. Follow Up / Return Precautions
Postpartum: [5][11][17]
- Continue magnesium sulfate for 24 hours after delivery
- BP typically dips within 48 hours then peaks on days 3–6 postpartum — critical monitoring window
- Postpartum BP check within 72 hours for severe hypertension; 7–10 days for all hypertensive disorders
- Home BP monitoring recommended; initiate/titrate antihypertensives to keep BP <150/100 mm Hg postpartum [5]
- Comprehensive postpartum visit at 4–12 weeks with CVD risk assessment [11]
Return precautions — instruct patients to seek immediate care for:
- Severe headache unresponsive to analgesics
- Visual changes (blurred vision, flashing lights, spots)
- Epigastric or RUQ pain
- Sudden swelling of face or hands
- Shortness of breath
- Seizure activity
- Decreased fetal movement (if antepartum)
Long-term counseling: [3][11][16]
- Preeclampsia recurrence risk in future pregnancies (especially if early-onset)
- Low-dose aspirin in future pregnancies for prevention
- Significantly elevated lifetime CVD risk — annual BP, lipid, and glucose screening recommended
- Lifestyle modifications: heart-healthy diet, exercise, weight management, smoking cessation
References
1. Gestational Hypertension and Preeclampsia: ACOG Practice Bulletin, Number 222. — Committee on Practice Bulletins—Obstetrics Obstetrics and Gynecology. 2020.
2. Calcium Supplementation During Pregnancy for Preventing Hypertensive Disorders and Related Problems. — Cluver CA, Rohwer C, Rohwer AC. The Cochrane Database of Systematic Reviews. 2025.
3. Preeclampsia. — Magee LA, Nicolaides KH, von Dadelszen P. The New England Journal of Medicine. 2022.
4. Preeclampsia-Pathophysiology and Clinical Presentations: JACC State-of-the-Art Review. — Ives CW, Sinkey R, Rajapreyar I, Tita ATN, Oparil S. Journal of the American College of Cardiology. 2020.
5. Hypertensive Disorders of Pregnancy. — Farahi N, Oluyadi F, Dotson AB. American Family Physician. 2024.
6. Cardiovascular Considerations in Caring for Pregnant Patients: A Scientific Statement From the American Heart Association. — Mehta LS, Warnes CA, Bradley E, et al. Circulation. 2020.
7. Pregnancy and the Liver. — Rahim MN, Williamson C, Kametas NA, Heneghan MA. Lancet. 2025.
8. Pre-Eclampsia. — Mol BWJ, Roberts CT, Thangaratinam S, et al. Lancet. 2016.
9. Hypertension Across a Woman's Life Cycle. — Wenger NK, Arnold A, Bairey Merz CN, et al. Journal of the American College of Cardiology. 2018.
10. Society for Maternal‐Fetal Medicine Special Statement: Updated checklists for preeclampsia risk‐factor screening to guide recommendations for prophylactic low‐dose aspirin. — , Jeny Ghartey, C. Andrew Combs, Pregnancy. 2026.
11. Preeclampsia: A Report and Recommendations of the Workshop of the Society for Maternal-Fetal Medicine and the Preeclampsia Foundation. — Society for Maternal-Fetal Medicine (SMFM). Electronic address: pubs@smfm.org, Louis JM, Parchem J, et al. American Journal of Obstetrics and Gynecology. 2022.
12. Screening for Hypertensive Disorders of Pregnancy: US Preventive Services Task Force Final Recommendation Statement. — US Preventive Services Task Force, Barry MJ, Nicholson WK, et al. The Journal of the American Medical Association. 2023.
13. Screening for Preeclampsia: US Preventive Services Task Force Recommendation Statement. — US Preventive Services Task Force, Bibbins-Domingo K, Grossman DC, et al. The Journal of the American Medical Association. 2017.
14. Team-Based Care of Women With Cardiovascular Disease From Pre-Conception Through Pregnancy And Postpartum: JACC Focus Seminar 1/5. — Davis MB, Arendt K, Bello NA, et al. Journal of the American College of Cardiology. 2021.
15. Preeclampsia: Recent Advances in Predicting, Preventing, and Managing the Maternal and Fetal Life-Threatening Condition. — Chang KJ, Seow KM, Chen KH. International Journal of Environmental Research and Public Health. 2023.
16. Long-Term Cardiovascular Risk and Maternal History of Pre-Eclampsia. — Palmiero P, Caretto P, Ciccone MM, Maiello M, On Behalf Of The I C I S C U Italian Chapter Of International Society Cardiovascular Ultrasound. Journal of Clinical Medicine. 2025.
17. Society for Maternal-Fetal Medicine Special Statement: Checklist for Postpartum Discharge of Women With Hypertensive Disorders. — Gibson KS, Hameed AB. American Journal of Obstetrics and Gynecology. 2020.