MFM Provider Education
Preeclampsia
Early Identification & Management
Evidence-based clinical update — diagnosis, surveillance, intervention, and long-term counseling
Hypertensive Disorder
ACOG PB #222
Provider Education
Epidemiology
Epidemiology & Impact
2–8%
of US pregnancies
affected
60%
higher risk
in Black women
#1
cause of maternal
morbidity worldwide
Long
-term CV risk for
mother & offspring
- Leading cause of maternal mortality globally — yet largely preventable with early identification
- Associated with preterm birth, IUGR, and placental abruption
- Racial disparity is structural — Black women face 60% higher risk independent of other factors
- Long-term cardiovascular sequelae for both mother and child
ACOG Practice Bulletin #222, 2020
Pathophysiology
Two-Stage Pathophysiology
Stage 1 — Early Pregnancy
Abnormal placentation: Inadequate trophoblast invasion and failure of spiral artery remodeling. Occurs in the first half of pregnancy — often clinically silent. Sets the stage for the maternal syndrome.
Stage 2 — Maternal Syndrome
Endothelial dysfunction: ↓ VEGF, ↑ sFlt-1, ↑ sEng. Systemic inflammation and oxidative stress. Hypertension and end-organ damage manifest clinically in the second half of pregnancy.
💡
The sFlt-1/PlGF ratio is increasingly used for short-term prediction of preeclampsia and can rule out preeclampsia within 1 week when the ratio is ≤38.
Diagnosis — ACOG 2019
Diagnostic Criteria (ACOG 2019)
New-onset hypertension after 20 weeks in a previously normotensive woman, plus at least one of the following:
| Criterion | Threshold |
|---|
| Blood Pressure | SBP ≥140 or DBP ≥90 mmHg on two occasions ≥4 hours apart |
| Proteinuria | ≥300 mg/24h, protein/creatinine ≥0.3, or dipstick ≥2+ |
| Thrombocytopenia | Platelets <100,000/µL |
| Renal insufficiency | Creatinine >1.1 mg/dL or doubling of baseline |
| Impaired liver function | Transaminases 2× upper limit of normal |
| Pulmonary edema | New-onset |
| Cerebral/visual symptoms | New-onset headache unresponsive to medication, or scotomata |
⚠️
Proteinuria is no longer required for diagnosis — any end-organ involvement is sufficient. BP can normalize between readings; do not dismiss the diagnosis on a single normal value.
Severe Features
Preeclampsia with Severe Features
- Severe hypertension: SBP ≥160 or DBP ≥110 mmHg
- Thrombocytopenia: Platelets <100,000/µL
- Liver dysfunction: Transaminases ≥2× normal + RUQ pain
- Renal dysfunction: Creatinine >1.1 mg/dL or doubling
- Pulmonary edema (new-onset)
- Persistent headache unresponsive to medication
- Visual symptoms: scotomata, blurring, or photophobia
- Severe RUQ or epigastric pain unresponsive to medication
⚠️
Severe features warrant hospitalization, aggressive BP control, seizure prophylaxis, and delivery planning. Delivery is the only definitive treatment. Headache + hyperreflexia does not predict seizure — magnesium is still indicated.
Prevention
Risk Stratification & First-Trimester Screening
High-Risk Factors (>8% risk)
Prior preeclampsia (especially early-onset) • Multifetal gestation • Chronic hypertension • Type 1 or 2 diabetes • Renal disease • Autoimmune disease (SLE, APS)
FMF Algorithm (11–13+6 weeks)
Maternal characteristics + MAP + uterine artery Doppler PI + serum PAPP-A and PlGF. Detection rate: ~75% for early-onset preeclampsia. ASPRE trial validated this approach.
💡
Moderate-risk factors include nulliparity, BMI >30, family history, age ≥35, prior adverse pregnancy outcome, IVF, and low socioeconomic status. ≥2 moderate-risk factors = aspirin indication.
Prevention
Aspirin Prophylaxis
81–162 mg
daily at bedtime
(162 mg for high-risk)
<16 wks
initiate — ideally
by 12 weeks
62%
reduction in early
preeclampsia (ASPRE)
| Parameter | Recommendation |
|---|
| Indication | ≥1 high-risk factor OR ≥2 moderate-risk factors (USPSTF/ACOG 2021) |
| Dose | 81–162 mg daily at bedtime; continue until delivery |
| NNT | 72 to prevent one case of preeclampsia |
| ASPRE trial | 62% reduction in early preeclampsia with 150 mg at bedtime (FMF-screened population) |
Surveillance
Antenatal Surveillance
Without Severe Features
BP monitoring 2× weekly (outpatient possible) • Weekly labs: CBC, LFTs, creatinine • Fetal NST/BPP 1–2× weekly from diagnosis • Growth ultrasound every 3 weeks
With Severe Features
Inpatient management at ≥34 weeks • Expectant management 23–33+6 weeks at tertiary center only • Daily labs + continuous/frequent BP monitoring • Daily fetal surveillance
⚠️
Trend labs serially — platelets are often the first to fall. BP can normalize between readings. Do not dismiss the diagnosis based on a single normal measurement.
Acute Management
Acute Severe Hypertension Management
Goal: Reduce SBP to 140–150 mmHg and DBP to 90–100 mmHg within 30–60 minutes.
| Agent | Dose | Notes |
|---|
| Labetalol IV | 20 mg → 40 mg → 80 mg q10min | Max 220 mg total; first-line |
| Hydralazine IV | 5–10 mg q20min | Max 20 mg total |
| Nifedipine PO | 10–20 mg q20min | Immediate release only — not extended |
⚠️
ACOG mandates treating sustained SBP ≥160 or DBP ≥110 mmHg within 30–60 minutes. Failure to treat promptly significantly increases maternal stroke risk. Document time-to-treatment.
Seizure Prophylaxis
Magnesium Sulfate Prophylaxis
Indications
Preeclampsia with severe features • During labor and 24–48 hours postpartum • Treatment and prevention of eclamptic seizures
Dosing
Loading: 4–6 g IV over 15–20 minutes
Maintenance: 2 g/hour continuous infusion
Monitoring
Deep tendon reflexes (discontinue if absent) • Respiratory rate >12/min • Urine output >25 mL/hour • Serum Mg if renal insufficiency (goal 4–7 mEq/L)
⚠️
Headache and hyperreflexia do not predict seizure. Magnesium is indicated for seizure prophylaxis in all severe-feature cases regardless of neurological symptoms.
Delivery
Delivery Timing & HELLP Syndrome
| Clinical Scenario | Delivery Timing |
|---|
| Preeclampsia without severe features | 37 0/7 weeks |
| Preeclampsia with severe features | 34 0/7 weeks |
| HELLP syndrome | 34 0/7 weeks |
| Eclampsia | After stabilization |
| Severe features + maternal instability | Immediate |
⚠️
HELLP (Hemolysis, Elevated Liver enzymes, Low Platelets): up to 20% present without hypertension or proteinuria. Monitor for DIC, liver hematoma/rupture, and acute renal failure. Administer betamethasone if delivery expected before 34 weeks.
Postpartum
Postpartum Management
Immediate (0–72 hours)
Continue magnesium sulfate 24–48 hours postpartum • Monitor BP closely — peaks 3–6 days postpartum, not immediately after delivery • Treat severe hypertension aggressively • Watch for new-onset postpartum preeclampsia/eclampsia
Antihypertensive Selection
Preferred: Labetalol, nifedipine (safe for breastfeeding)
Avoid: Methyldopa (slow onset)
Caution: ACE inhibitors/ARBs (verify breastfeeding safety)
NSAIDs: Use with caution — may worsen hypertension and renal function
⚠️
Ensure BP check at 7–10 days postpartum (not just 6 weeks). Postpartum hypertension peaks days 3–6 — patients discharged before this window are at risk.
Long-Term & Summary
Long-Term Risk & Clinical Action Items
Long-Term Cardiovascular Risk
2–4× increased CV disease risk • 2× stroke risk • Earlier onset of events (40s–50s) • Risk of chronic hypertension, metabolic syndrome, and diabetes. AHA 2021: preeclampsia is an independent CV risk factor. Annual BP checks + lifestyle counseling lifelong.
Recurrence Risk
Term preeclampsia → 5–7% recurrence • Early-onset → 25–65% • Two prior pregnancies → 32% • Severe preeclampsia → up to 40%.
Preconception: optimize chronic conditions + aspirin before 16 weeks in next pregnancy.
- Screen early — risk-stratify at first prenatal visit
- Manage severe features — BP control + MgSO₄ + deliver appropriately
- Prevent — aspirin <16 weeks for eligible patients
- Time delivery correctly — balance maternal and fetal risks
- Diagnose accurately — end-organ involvement; proteinuria not required
- Follow long-term — cardiovascular risk counseling + ongoing primary care
ACOG Practice Bulletin #222 • USPSTF 2021 • AHA 2021 • ASPRE Trial
This material supports — and does not replace — individualized clinical judgment.