Preeclampsia Management

Definition & Diagnosis Recap

• Proteinuria (≥300 mg/24 hr, protein:creatinine ≥0.3, or dipstick 2+)
• Thrombocytopenia (<100,000/μL)
• Renal insufficiency (creatinine >1.1 mg/dL or doubling of baseline)
• Impaired liver function (transaminases ≥2× upper limit)
• Pulmonary edema
• New-onset headache unresponsive to medication / visual symptoms

Three Core Principles of Management

1. Delivery is always appropriate therapy for the mother - but not always for the fetus. The only justification for delaying delivery is to allow fetal maturation.
2. Treating the signs (BP, proteinuria) does not fix the pathology. Vasospasm and poor perfusion are the underlying drivers. Natriuresis can actually worsen fetal outcome by further reducing already-restricted plasma volume.
3. Pathologic changes precede clinical diagnosis - irreversible fetal compromise can exist before criteria are met.

Part 1: Preeclampsia WITHOUT Severe Features

At Term (≥37 weeks)

• Prompt delivery is indicated. A Dutch RCT confirmed immediate induction = improved maternal outcome with similar neonatal outcomes.

Preterm (<37 weeks)

• Expectant management with:
  • Antenatal corticosteroids
  • Frequent maternal and fetal monitoring
  • Serial BP checks, labs, fetal non-stress tests / BPP
  • Bed rest (usually outpatient if stable)

• Persistent reversed end-diastolic flow in umbilical artery
• Abnormal fetal testing
• Fetal anomaly incompatible with survival

Part 2: Preeclampsia WITH Severe Features

• BP ≥160/110 mmHg on two readings ≥4 hrs apart
• Thrombocytopenia <100,000/μL
• Hepatic transaminases ≥2× upper limit, RUQ/epigastric pain
• Creatinine >1.1 mg/dL or doubling of baseline
• Pulmonary edema
• New-onset headache unresponsive to medication
• Visual disturbances

At Term (≥37 weeks) or Late Preterm (34-36+6 weeks)

• Deliver. Do not delay for corticosteroids, but can administer during induction if >12 hours anticipated.

Early Preterm (<34 weeks) - Expectant Management May Be Considered

• HELLP syndrome develops
• Persistent neurological symptoms or RUQ pain
• Platelets <100,000/μL, transaminases >2× ULN, creatinine >1.1 mg/dL
• Reversed end-diastolic flow
• Labour or PROM

Part 3: Antihypertensive Therapy

First-Line Acute Agents

Maintenance Antihypertensives (chronic/outpatient)

• Labetalol 200-400 mg PO BID-TID
• Methyldopa 250-500 mg PO BID-TID (safe in pregnancy, minimal fetal effects)
• Nifedipine XL 30-60 mg PO daily
• Avoid: ACE inhibitors, ARBs (teratogenic/fetotoxic)

Part 4: Magnesium Sulfate - Seizure Prophylaxis & Treatment

• Seizure prophylaxis in severe preeclampsia (during labor and for 24-48 hrs postpartum)
• Treatment of eclamptic seizures

Dosing (Standard Parkland Protocol)

• Loading dose: 4-6 g IV over 15-20 minutes
• Maintenance: 2 g/hr IV continuous infusion
• Continue 24-48 hours postpartum

Monitoring for Toxicity

Part 5: Fluid Management

• Restrict IV fluids - avoid aggressive hydration (risk of pulmonary edema)
• Target urine output >25 mL/hr
• Avoid diuretics unless pulmonary edema is present (diuretics worsen the already-contracted plasma volume)
• Avoid hyperosmotic agents

Part 6: Intrapartum Management

• Mode of delivery: Vaginal delivery is preferred; cesarean section reserved for standard obstetric indications
• Regional anesthesia (epidural) is preferred - helps BP control
• Continue magnesium sulfate throughout labor and 24 hrs postpartum
• Low threshold for continuous fetal monitoring

Part 7: Postpartum Management

• BP can worsen in the first 3-5 days postpartum - highest risk for eclampsia is 24-48 hrs after delivery
• Continue magnesium sulfate for 24-48 hours postpartum
• Treat BP ≥150/100 mmHg postpartum
• Oral options: labetalol, nifedipine XL, methyldopa
• A 2024 systematic review (PMID 39806714) supports oral antihypertensives over diuretics for postpartum hypertension management
• Counsel on long-term cardiovascular risk - preeclampsia is associated with 2× increased risk of heart disease and stroke later in life

Part 8: Eclampsia Management (Seizure)

1. Airway, breathing, circulation - lateral decubitus position, supplemental O2
2. Magnesium sulfate 4-6 g IV over 15-20 min, then 2 g/hr
3. Control BP after seizure control if diastolic >105 mmHg
4. Labs: CBC, platelets, LFTs, BUN, creatinine
5. CT head if: altered consciousness, focal neurological signs, or seizures persist
6. Deliver after maternal stabilization

Summary Decision Tree

Preeclampsia diagnosed
        |
   _____|______
  |            |
Without SF    With SF
  |                 |
≥37 wk → Deliver   ≥34 wk → Deliver
<37 wk → Expectant  <34 wk → Steroids + MgSO4 + Close monitoring
          management         → Reassess 48 hrs
          + steroids         → Deliver if deterioration

• Creasy & Resnik's Maternal-Fetal Medicine, pp. 1069-1072
• Rosen's Emergency Medicine, pp. 3357-3358
• Recent evidence: Anti-hypertensive therapy network meta-analysis [PMID 38488570, 2024]; Postpartum antihypertensives review [PMID 39806714, 2024]