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Eclampsia / Seizure in Pregnancy

VERSION: 1.0 CREATED: January 31, 2026 STATUS: Approved


DIAGNOSIS: Eclampsia / Seizure in Pregnancy

ICD-10: O15.0 (Eclampsia complicating pregnancy), O15.1 (Eclampsia complicating labor), O15.2 (Eclampsia complicating the puerperium), O15.9 (Eclampsia, unspecified as to time period), O14.10 (Severe pre-eclampsia, unspecified trimester), O14.12 (Severe pre-eclampsia, second trimester), O14.13 (Severe pre-eclampsia, third trimester), O14.20 (HELLP syndrome, unspecified trimester), G40.909 (Epilepsy in pregnancy — known epilepsy presenting during pregnancy)

CPT CODES: 70450 (CT head), 70553 (MRI brain), 95816 (EEG), 80053 (CMP), 85025 (CBC), 85610 (PT/INR), 82553 (LDH), 84450 (AST), 82040 (albumin), 82728 (ferritin), 83036 (HbA1c), 84703 (hCG), 81003 (urinalysis), 82570 (urine protein/creatinine ratio)

SYNONYMS: Eclampsia, eclamptic seizure, seizure in pregnancy, seizure in preeclampsia, pregnancy-associated seizure, puerperal seizure, postpartum eclampsia, late postpartum eclampsia, hypertensive encephalopathy of pregnancy, PRES in pregnancy, eclamptic encephalopathy, toxemia seizure, gestational seizure

SCOPE: Neurological evaluation and management of seizures occurring during pregnancy and the postpartum period. Covers eclamptic seizures, PRES overlap with eclampsia, management of known epilepsy during pregnancy, acute seizure treatment including magnesium sulfate protocol, blood pressure management, fetal considerations, and postpartum seizure management. Excludes isolated preeclampsia without seizure (obstetric management), non-pregnant seizure evaluation (see New Onset Seizure), and chronic epilepsy management (see Epilepsy Chronic Management).


PRIORITY KEY: STAT = Immediate | URGENT = Within hours | ROUTINE = Standard | EXT = Extended/atypical cases | - = Not applicable to this setting

═══════════════════════════════════════════════════════════════ SECTION A: ACTION ITEMS ═══════════════════════════════════════════════════════════════

1. LABORATORY WORKUP

1A. Essential/Core Labs

Test ED HOSP OPD ICU Rationale Target Finding
CBC with differential and platelets (CPT 85025) STAT STAT ROUTINE STAT HELLP syndrome screening (hemolysis, elevated liver enzymes, low platelets); DIC; infection; baseline for delivery planning Platelets >100K; <100K → HELLP; schistocytes → microangiopathic hemolysis
CMP (BMP + LFTs) (CPT 80053) STAT STAT ROUTINE STAT Hepatic transaminases (HELLP); renal function (preeclampsia with severe features); electrolytes; glucose; uric acid trend AST/ALT <70 IU/L; elevated → HELLP/severe preeclampsia; creatinine <0.9 mg/dL; elevated → renal involvement
Uric acid (CPT 84550) STAT STAT ROUTINE STAT Elevated in preeclampsia; correlates with disease severity; useful trending parameter <5.5 mg/dL in pregnancy; >6.0 → severe preeclampsia; trend upward concerning
LDH (CPT 82553) STAT STAT ROUTINE STAT Hemolysis marker for HELLP; elevated LDH with low haptoglobin and schistocytes confirms hemolysis <600 IU/L; elevated → hemolysis component of HELLP
PT/INR, PTT, fibrinogen (CPT 85610, 85730, 85384) STAT STAT - STAT Coagulopathy screening; DIC in severe preeclampsia/HELLP; baseline before delivery Normal; fibrinogen <300 mg/dL concerning (normally elevated in pregnancy >400); DIC if fibrinogen <200 + elevated D-dimer
Haptoglobin (CPT 83010) STAT STAT - STAT Hemolysis marker; absent or very low in HELLP Normal; <25 mg/dL → hemolysis
Peripheral blood smear (CPT 85007) STAT STAT - STAT Schistocytes confirm microangiopathic hemolysis (HELLP, TTP, HUS) No schistocytes; present → microangiopathic process
Urinalysis with protein (CPT 81003) STAT STAT ROUTINE STAT Proteinuria confirms preeclampsia diagnosis; quantification needed <300 mg/24h; ≥300 mg → proteinuria (preeclampsia diagnostic criterion)
Urine protein/creatinine ratio (CPT 84156/82570) STAT STAT ROUTINE STAT Rapid assessment of proteinuria; correlates with 24h collection; >0.3 diagnostic <0.3; ≥0.3 → significant proteinuria
Blood glucose (CPT 82947) STAT STAT ROUTINE STAT Hypoglycemia as seizure cause; gestational diabetes assessment 60-180 mg/dL; low → treat immediately
Magnesium level (CPT 83735) STAT STAT ROUTINE STAT Baseline before MgSO4 therapy; monitor during infusion for toxicity; therapeutic range 4-7 mEq/L for seizure prophylaxis Baseline 1.5-2.5 mEq/L; therapeutic on MgSO4: 4-7 mEq/L; toxic >7 (loss of reflexes), >10 (respiratory depression), >12 (cardiac arrest)
Calcium, ionized (CPT 82330) STAT STAT - STAT Hypocalcemia as seizure cause; MgSO4 can cause hypocalcemia Normal; low → replete
Type and screen (CPT 86900/86901) STAT STAT - STAT Preparation for potential emergent delivery; hemorrhage risk in HELLP/DIC Type and antibody screen available
ASM levels (if on ASMs for epilepsy) (CPT 80201-80299) STAT STAT ROUTINE STAT Pregnancy alters ASM pharmacokinetics (increased clearance, volume distribution, decreased protein binding); levels often subtherapeutic Compare to pre-pregnancy baseline; lamotrigine drops 50-70%; levetiracetam drops ~60%; free levels preferred

1B. Extended Workup (Second-line)

Test ED HOSP OPD ICU Rationale Target Finding
D-dimer (CPT 85379) STAT STAT - STAT DIC screening; normally elevated in pregnancy but very high suggests DIC Mildly elevated (normal in pregnancy); markedly elevated → DIC
Reticulocyte count (CPT 85044) - URGENT - URGENT Elevated in hemolytic anemia (HELLP); marrow response to hemolysis Elevated → active hemolysis; low → marrow suppression
TSH (CPT 84443) - ROUTINE ROUTINE - Thyroid storm can cause seizures; postpartum thyroiditis Normal
Ammonia (CPT 82140) STAT STAT - STAT Acute fatty liver of pregnancy (AFLP) can cause seizures; valproate encephalopathy if on VPA <35 μmol/L; elevated → AFLP or VPA toxicity
Lipase (CPT 83690) STAT STAT - STAT Pancreatitis associated with HELLP; severe epigastric pain evaluation Normal; elevated → pancreatitis
Lactate (CPT 83605) STAT STAT - STAT Postictal elevation; persistent elevation → hemodynamic compromise or hepatic dysfunction Mildly elevated postictal (resolves in 2h); persistent → concerning
Cortisol, AM (CPT 82533) - ROUTINE - - Adrenal insufficiency (Sheehan syndrome in postpartum); normally elevated in pregnancy Normal for pregnancy (elevated baseline)

1C. Rare/Specialized (Refractory or Atypical)

Test ED HOSP OPD ICU Rationale Target Finding
ADAMTS13 activity (CPT 85397) - URGENT - URGENT Thrombotic thrombocytopenic purpura (TTP) can mimic HELLP/eclampsia; low ADAMTS13 (<10%) diagnostic >10% (normal); <10% → TTP; requires plasma exchange
Antiphospholipid antibody panel (CPT 86235, 86147) - EXT ROUTINE - Antiphospholipid syndrome increases preeclampsia and stroke risk; lupus anticoagulant, anticardiolipin, anti-β2-glycoprotein I Negative; positive → anticoagulation; thrombophilia workup
Complement levels (C3, C4) (CPT 86160, 86161) - EXT EXT - Low in lupus nephritis, atypical HUS, complement-mediated TMA mimicking preeclampsia Normal; low → autoimmune or complement-mediated process
Autoimmune encephalitis antibody panel - EXT EXT - If seizures refractory to MgSO4 and antihypertensives; atypical presentation; postpartum encephalitis Negative; positive → immunotherapy
Toxicology screen (CPT 80307) STAT STAT - STAT Cocaine, methamphetamine → hypertensive crisis and seizures in pregnancy; occult substance use Negative; positive → specific management
Thrombophilia panel - - EXT - If early-onset severe preeclampsia (<34 weeks); recurrent preeclampsia; factor V Leiden, prothrombin mutation, protein C/S, antithrombin III Normal; positive → hematology referral for future pregnancy planning

2. DIAGNOSTIC IMAGING & STUDIES

2A. Essential/First-line

Study ED HOSP OPD ICU Timing Target Finding Contraindications
CT head without contrast (CPT 70450) STAT STAT - STAT First-line acute imaging if eclamptic seizure; rule out hemorrhage, edema, herniation; safe in pregnancy (low dose, shield abdomen) No hemorrhage; may show posterior cerebral edema (PRES pattern); mass effect None (shield abdomen; benefit outweighs minimal fetal risk)
MRI brain without contrast (CPT 70551) - URGENT ROUTINE URGENT Preferred imaging after initial CT; PRES evaluation (T2/FLAIR hyperintensity in posterior cerebral regions); no gadolinium in pregnancy unless absolutely necessary PRES: bilateral symmetric T2/FLAIR hyperintensity in parieto-occipital regions; may involve frontal, temporal, brainstem, cerebellum; DWI to differentiate vasogenic (PRES) from cytotoxic edema (stroke) MRI-incompatible implants; avoid gadolinium if possible (crosses placenta)
MRA head and neck (CPT 70544/70547) - URGENT - URGENT If concern for cerebral venous thrombosis (CVT), arterial dissection, or vasospasm; CVT risk elevated in pregnancy/postpartum Normal; CVT (absent flow in sinuses); arterial narrowing → vasospasm (RCVS overlap); dissection Same as MRI
ECG (12-lead) (CPT 93000) STAT STAT ROUTINE STAT Cardiac evaluation; arrhythmia; cardiomyopathy (peripartum); magnesium effects on conduction Normal; PR prolongation (Mg effect); arrhythmia → cardiology None
Fetal monitoring (non-stress test / CTG) STAT STAT - STAT Fetal heart rate monitoring; assess for fetal distress during/after maternal seizure; placental abruption detection Reassuring FHR (reactive NST); non-reassuring → emergent delivery planning None

2B. Extended

Study ED HOSP OPD ICU Timing Target Finding Contraindications
MRV brain (CPT 70546) - URGENT - URGENT Cerebral venous thrombosis (CVT); pregnancy/postpartum is major risk factor; headache + seizure + focal deficit → must exclude Normal venous sinuses; CVT → anticoagulation Same as MRI
EEG (routine) (CPT 95816) - URGENT ROUTINE - If seizures recur despite MgSO4; diagnostic uncertainty (eclampsia vs epilepsy vs NCSE); persistent altered mental status Normal background or diffuse slowing (eclampsia); epileptiform discharges → epilepsy; NCSE patterns None
Continuous EEG (cEEG) (CPT 95700) - STAT - STAT Persistent altered mental status after eclamptic seizure; concern for NCSE; refractory seizures Ictal patterns; NCSE; background assessment None; resource-dependent
Echocardiogram (CPT 93306) - URGENT - URGENT Peripartum cardiomyopathy; pulmonary edema in severe preeclampsia; cardiac function assessment Normal EF (>55%); reduced EF → peripartum cardiomyopathy; pulmonary hypertension None
Chest X-ray (CPT 71046) STAT STAT - STAT Pulmonary edema (common in severe preeclampsia); aspiration after seizure; ETT position Clear lungs; bilateral edema → fluid overload/preeclampsia; infiltrate → aspiration Shield abdomen
Obstetric ultrasound (CPT 76805) STAT STAT - STAT Fetal viability and growth; placental abruption evaluation; amniotic fluid assessment Normal fetal growth; abruption → emergent delivery; oligohydramnios → uteroplacental insufficiency None

2C. Rare/Specialized

Study ED HOSP OPD ICU Timing Target Finding Contraindications
CT angiography head (CPT 70496) - URGENT - URGENT If concern for vasospasm (RCVS), arterial dissection, or aneurysm; when MRA unavailable or inconclusive Vasospasm; dissection; aneurysm Contrast risk to fetus (use only if MRA unavailable and diagnosis critical); iodinated contrast crosses placenta
Conventional angiography (CPT 36224) - EXT - EXT Gold standard for cerebral vasospasm if imaging equivocal and clinical suspicion high Multifocal segmental vasoconstriction (RCVS pattern) Invasive; radiation; contrast; reserve for equivocal cases

3. TREATMENT

3A. Acute/Emergent

Treatment Route Indication Dosing Contraindications Monitoring ED HOSP OPD ICU
Magnesium sulfate (MgSO4) — loading dose IV FIRST-LINE for eclamptic seizures and seizure prophylaxis in severe preeclampsia; superior to phenytoin and diazepam for eclampsia 4-6 g IV over 15-20 min :: IV :: q4h :: 4-6 g IV loading dose in 100 mL NS over 15-20 min; Zuspan regimen: 4 g IV load + 1 g/h maintenance; Pritchard regimen: 4 g IV + 10 g IM load (5 g each buttock) + 5 g IM q4h Myasthenia gravis; severe renal failure (adjust dose); heart block Magnesium level q4-6h (target 4-7 mEq/L); deep tendon reflexes q1h (FIRST SIGN of toxicity = loss of patellar reflex); respiratory rate q1h (>12/min); urine output q1h (>25 mL/h); have calcium gluconate at bedside STAT STAT - STAT
Magnesium sulfate (MgSO4) — maintenance IV Continued seizure prophylaxis after loading dose; continue for 24-48h postpartum (eclampsia risk persists postpartum) 1-2 g/h continuous infusion :: IV :: continuous :: 1 g/h standard maintenance; increase to 2 g/h if seizure recurs or in severe preeclampsia; continue 24h postpartum (48h if persistent severe features); reduce to 0.5 g/h if CrCl <30 Same as loading; monitor for toxicity Same as loading; reduce dose if reflexes diminish or urine output drops STAT STAT - STAT
Calcium gluconate (MgSO4 antidote) IV MAGNESIUM TOXICITY RESCUE: Respiratory depression, loss of reflexes, cardiac arrest from Mg toxicity 1 g IV over 3 min :: IV :: once :: 1 g (10 mL of 10% solution) IV over 3 min; may repeat; MUST be at bedside whenever MgSO4 infusing None in emergency Cardiac monitoring; respiratory status; repeat Mg level STAT STAT - STAT
Labetalol IV First-line antihypertensive for acute severe hypertension in pregnancy (SBP ≥160 or DBP ≥110); prevents stroke 20 mg IV; 40 mg IV; 80 mg IV :: IV :: continuous :: 20 mg IV push over 2 min; if BP not controlled in 10 min → 40 mg; then 80 mg; max 300 mg total; then start infusion 1-2 mg/min Asthma; decompensated heart failure; second/third-degree heart block; heart rate <60 BP q5 min during IV bolus; heart rate; fetal monitoring (labetalol safe in pregnancy) STAT STAT - STAT
Hydralazine IV Second-line antihypertensive for acute severe hypertension in pregnancy; alternative when labetalol contraindicated 5 mg IV; 10 mg IV :: IV :: once :: 5 mg IV over 1-2 min; if BP not controlled in 20 min → repeat 5-10 mg; max 20 mg total; then reassess Coronary artery disease; mitral stenosis; tachycardia BP q5 min; heart rate (reflex tachycardia common); fetal monitoring STAT STAT - STAT
Nifedipine (immediate-release) PO Oral antihypertensive for severe hypertension when IV access delayed or as transition from IV therapy 10 mg PO; 20 mg PO :: PO :: daily :: 10-20 mg PO; may repeat in 30 min if needed; max 30 mg in acute setting; transition to extended-release 30-60 mg daily Concurrent MgSO4 (theoretical concern for potentiated hypotension — monitor closely but combination is used); severe aortic stenosis BP q15 min after first dose; fetal monitoring; avoid sublingual route (unpredictable absorption) STAT STAT - STAT
Lorazepam IV Second-line for eclamptic seizure not responding to MgSO4; or while MgSO4 loading in progress 4 mg IV push :: IV :: once :: 4 mg IV push over 2 min; may repeat x1 in 5 min; max 8 mg; benzodiazepines cross placenta — anticipate neonatal sedation Severe respiratory depression; use only if MgSO4 inadequate; short-term use only Respiratory rate; SpO2; neonatal assessment at delivery; have airway equipment ready STAT STAT - STAT
Levetiracetam IV, PO ASM for recurrent seizures after MgSO4 failure; preferred over phenytoin in pregnancy due to better safety profile; for known epilepsy patients needing IV loading 1000 mg IV load; 500 mg IV q12h :: IV :: q12h :: Load 1000-1500 mg IV over 15 min; maintenance 500-1000 mg IV/PO q12h; renal dosing if CrCl <50 Hypersensitivity Renal function; psychiatric side effects; safe in pregnancy (low teratogenicity); safe in breastfeeding STAT STAT ROUTINE STAT

3B. Symptomatic Treatments

Treatment Route Indication Dosing Contraindications Monitoring ED HOSP OPD ICU
Acetaminophen PO, IV Headache in eclampsia/preeclampsia; safe in pregnancy; first-line analgesic 650-1000 mg q6h :: PO :: q6h :: 650-1000 mg PO/IV q6h; max 3000 mg/day in pregnancy; avoid in hepatic impairment (HELLP) Severe hepatic impairment (HELLP with transaminases >5x ULN); allergy LFTs if HELLP STAT STAT ROUTINE STAT
Ondansetron IV, PO Nausea/vomiting in eclampsia/severe preeclampsia; safe in pregnancy 4 mg IV :: IV :: q8h PRN :: 4 mg IV/PO q8h PRN; max 16 mg/day QT prolongation; first trimester concern (some data, generally considered safe) QTc if risk factors STAT STAT ROUTINE STAT
Labetalol (oral maintenance) PO Transition from IV to oral BP control in preeclampsia; maintenance antihypertensive 100 mg BID; 200 mg BID; 300 mg TID :: PO :: TID :: Start 100 mg PO BID; increase by 100 mg q12h as needed; target BP <150/100 antepartum; max 2400 mg/day Asthma; bradycardia; decompensated CHF BP; heart rate; fetal monitoring - ROUTINE ROUTINE -
Nifedipine extended-release PO Oral antihypertensive maintenance for preeclampsia; calcium channel blocker safe in pregnancy 30 mg daily; 60 mg daily; 90 mg daily :: PO :: daily :: Start 30 mg daily; increase by 30 mg q3-7d; max 120 mg/day; swallow whole, do not crush Severe aortic stenosis; hypotension BP; heart rate; peripheral edema; fetal monitoring - ROUTINE ROUTINE -

3C. Second-line/Refractory

Treatment Route Indication Dosing Contraindications Monitoring ED HOSP OPD ICU
Phenytoin (fosphenytoin) IV Third-line for eclamptic seizures refractory to MgSO4 + lorazepam; historically used but INFERIOR to MgSO4 for eclampsia 20 mg PE/kg IV :: IV :: once :: 20 mg phenytoin equivalents (PE)/kg IV at ≤150 mg PE/min; maintenance 5 mg PE/kg/day; check free phenytoin level (protein binding altered in pregnancy) Sinus bradycardia; second/third-degree AV block; Stokes-Adams syndrome; TERATOGENIC (fetal hydantoin syndrome) — use only if no alternative Cardiac monitoring during infusion; free phenytoin level (not total); BP; fetal monitoring STAT STAT - STAT
Nicardipine infusion IV Refractory severe hypertension not controlled by labetalol + hydralazine; ICU setting 5 mg/h titrated to 15 mg/h :: IV :: continuous :: Start 5 mg/h IV; increase by 2.5 mg/h q5-15min; max 15 mg/h; target SBP 140-155; reduce BP no more than 25% in first hour Severe aortic stenosis; compensatory hypertension Arterial line; continuous BP; fetal monitoring - - - STAT
Sodium nitroprusside IV Life-threatening hypertensive emergency refractory to all other agents; LAST RESORT in pregnancy due to cyanide risk to fetus 0.25-0.5 mcg/kg/min :: IV :: q5min :: Start 0.25 mcg/kg/min; titrate by 0.5 mcg/kg/min q5min; max 2 mcg/kg/min; use for shortest duration possible; CYANIDE TOXICITY risk to fetus — LAST RESORT Compensatory hypertension; hepatic insufficiency; coarctation of aorta Arterial line mandatory; thiocyanate levels if >24h; FETAL MONITORING — cyanide crosses placenta - - - STAT
Delivery Surgical/vaginal DEFINITIVE TREATMENT for eclampsia: Delivery of fetus and placenta cures eclampsia in most cases N/A :: Obstetric :: once :: Plan delivery after maternal stabilization (seizure control + BP control); ≥34 weeks: delivery recommended; <34 weeks: consider steroids for fetal lung maturity if maternal condition allows 24-48h delay; emergent C-section if fetal distress Maternal instability precluding anesthesia (stabilize first) Continuous fetal monitoring; maternal hemodynamics; postpartum MgSO4 continuation 24-48h STAT STAT - STAT

3D. ASM Safety in Pregnancy / Postpartum

Treatment Route Indication Dosing Pre-Treatment Requirements Contraindications Monitoring ED HOSP OPD ICU
Lamotrigine PO Preferred ASM in pregnancy for known epilepsy; lowest teratogenicity risk among effective broad-spectrum ASMs; requires dose monitoring Individualized per levels :: PO :: monthly :: Monitor levels monthly during pregnancy (drops 50-70%); increase dose to maintain pre-pregnancy level; reduce dose by 25% within first 2 weeks postpartum then rapidly taper to pre-pregnancy dose over next 2 weeks Pre-pregnancy lamotrigine level as target SJS/TEN with rapid dose changes; do not increase faster than 50 mg q2wk Monthly lamotrigine levels; postpartum level within 1 week of delivery; toxicity symptoms (diplopia, ataxia) as levels rebound postpartum - ROUTINE ROUTINE -
Levetiracetam PO Preferred ASM in pregnancy; low teratogenicity; safe in breastfeeding; renal elimination (no hepatic interactions) Individualized per levels :: PO :: per protocol :: Monitor levels each trimester (decreases ~60%); increase dose to maintain seizure control; renal clearance increases in pregnancy; postpartum dose reduction needed Pre-pregnancy level as target Hypersensitivity; dose adjust for renal function Levels each trimester; psychiatric symptoms; renal function; postpartum reduction - ROUTINE ROUTINE -
Folic acid (high-dose preconception) PO Neural tube defect prevention in women with epilepsy; ALL women on ASMs planning pregnancy 4 mg daily :: PO :: daily :: 4 mg daily starting ≥3 months before conception; continue through first trimester; 1 mg daily maintenance after None Few Serum folate - ROUTINE ROUTINE -
Vitamin K (neonatal) IM All neonates born to mothers on enzyme-inducing ASMs; hemorrhagic disease of newborn prevention 1 mg IM at birth :: IM :: once :: 1 mg vitamin K IM to neonate at delivery; standard of care but especially critical with enzyme-inducing maternal ASMs None None Neonatal coagulation studies if clinically indicated - ROUTINE - -

4. OTHER RECOMMENDATIONS

4A. Referrals & Consults

Recommendation ED HOSP OPD ICU
OB/GYN or Maternal-Fetal Medicine (MFM) STAT consultation for all eclamptic seizures for delivery planning and fetal assessment STAT STAT - STAT
Neurology consultation for eclamptic seizure evaluation; PRES vs CVT vs other neurological cause; ASM management in known epilepsy STAT STAT ROUTINE STAT
Anesthesiology consultation for delivery planning; epidural/spinal safety; airway assessment if intubated; magnesium-neuromuscular blocker interactions - URGENT - URGENT
Neonatology or pediatrics notification for delivery; assess neonatal effects of maternal seizure, magnesium, and ASMs - URGENT - URGENT
Hematology consultation if HELLP with severe thrombocytopenia (<50K), suspected TTP (ADAMTS13 pending), or DIC - URGENT - URGENT
Nephrology consultation if acute kidney injury (creatinine >1.1 mg/dL in pregnancy) or persistent proteinuria postpartum - ROUTINE ROUTINE ROUTINE
Postpartum neurology follow-up in 2-4 weeks for MRI review, ASM management, and recurrence risk counseling - ROUTINE ROUTINE -
Postpartum OB follow-up in 1-2 weeks for BP monitoring, proteinuria resolution, and future pregnancy counseling - ROUTINE ROUTINE -

4B. Patient Instructions

Recommendation ED HOSP OPD
Return to ED immediately if new seizure, severe headache not responsive to acetaminophen, visual changes (blurring, scotomata, blindness), right upper quadrant pain, or sudden swelling of face/hands (preeclampsia warning signs) STAT STAT ROUTINE
Continue magnesium sulfate monitoring in hospital for 24-48 hours after delivery; do not leave against medical advice during this critical window - STAT -
Postpartum eclampsia can occur up to 6 weeks after delivery; any new seizure, severe headache, or visual changes in the postpartum period requires emergency evaluation - ROUTINE ROUTINE
If on ASMs for epilepsy: do NOT stop medications during pregnancy; benefits of seizure prevention outweigh teratogenicity risk of most ASMs; discuss any changes with neurologist - ROUTINE ROUTINE
Breastfeeding is generally safe with most ASMs (lamotrigine, levetiracetam, valproate, carbamazepine); monitor infant for sedation; discuss with neurologist and pediatrician - ROUTINE ROUTINE
Monitor blood pressure at home daily for 6 weeks postpartum using validated automated cuff; record and bring to follow-up; seek care if SBP ≥150 or DBP ≥100 - ROUTINE ROUTINE
Future pregnancies: preeclampsia recurrence risk is 15-25%; eclampsia recurrence ~2%; discuss timing and planning with MFM - - ROUTINE

4C. Lifestyle & Prevention

Recommendation ED HOSP OPD
Low-dose aspirin 81 mg daily starting at 12-16 weeks in future pregnancies for preeclampsia prevention (recommended for women with prior preeclampsia/eclampsia) - - ROUTINE
Blood pressure optimization before future pregnancies; target <130/80; weight management and regular exercise reduce preeclampsia risk - - ROUTINE
Calcium supplementation 1000-2000 mg daily in future pregnancies may reduce preeclampsia risk (especially if baseline dietary calcium is low) - - ROUTINE
Adequate sleep and stress management during pregnancy and postpartum to reduce seizure threshold and support recovery - ROUTINE ROUTINE
Smoking cessation and alcohol avoidance throughout pregnancy and postpartum - ROUTINE ROUTINE

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5. DIFFERENTIAL DIAGNOSIS

Alternative Diagnosis Key Distinguishing Features Tests to Differentiate
Eclampsia (primary diagnosis) New-onset seizure in pregnancy/postpartum with hypertension (≥140/90) and proteinuria; >20 weeks gestation; may occur without preceding preeclampsia diagnosis BP, urinalysis, preeclampsia labs; clinical diagnosis
PRES (posterior reversible encephalopathy syndrome) Overlaps heavily with eclampsia; posterior cerebral edema on MRI; may occur with or without eclampsia MRI (T2/FLAIR posterior predominant edema); DWI (vasogenic not cytotoxic edema); clinical overlap — treat both
Cerebral venous thrombosis (CVT) Headache, seizures, focal deficits; pregnancy/postpartum is major risk factor; may have hemorrhagic infarct MRV (absent venous flow); D-dimer (very elevated); CT venogram
Epilepsy (known, during pregnancy) Pre-existing seizure disorder; may have breakthrough due to decreased ASM levels; no hypertension/proteinuria ASM levels (subtherapeutic); normal BP; no proteinuria; prior epilepsy history
Ischemic stroke Sudden focal deficit; may have seizure at onset; pregnancy increases ischemic stroke risk 3-13x MRI/DWI (restricted diffusion); CTA/MRA (occlusion); onset with focal deficit
Intracerebral hemorrhage Severe headache; focal deficit; may have seizure; hypertension; coagulopathy (HELLP/DIC) CT head (hyperdense lesion); coagulation studies; platelet count
RCVS (reversible cerebral vasoconstriction syndrome) Thunderclap headache; seizures; focal deficits; angiography shows segmental vasoconstriction; overlaps with eclampsia/PRES CTA/MRA (multifocal narrowing); serial imaging (resolves over weeks)
Thrombotic thrombocytopenic purpura (TTP) Microangiopathic hemolytic anemia + thrombocytopenia; may mimic HELLP; seizures from TMA ADAMTS13 <10%; schistocytes; severe thrombocytopenia
Meningoencephalitis Fever, headache, altered mental status, seizures; may be viral (HSV) or bacterial CSF analysis; MRI (temporal lobe enhancement in HSV); cultures
Metabolic (hypoglycemia, hyponatremia, hypocalcemia) Correctable metabolic abnormalities; no hypertension/proteinuria BMP; glucose; calcium; magnesium
Acute fatty liver of pregnancy (AFLP) Third trimester; nausea, vomiting, abdominal pain, coagulopathy, hypoglycemia, hyperammonemia Ammonia (elevated); glucose (low); fibrinogen (low); LFTs (elevated); imaging (fatty liver)

Red Flags for Non-Eclamptic Cause

Red Flag Concern Action
Seizure before 20 weeks gestation Eclampsia rare <20 wks; consider epilepsy, structural lesion, metabolic Full neurologic workup; MRI; EEG
Normal blood pressure with seizure Not classic eclampsia (though 20% of eclampsia occurs with "normal" BP) Consider CVT, epilepsy, metabolic; MRV; ASM levels
Focal neurologic deficit persistent >24h Stroke (ischemic or hemorrhagic); CVT with infarction MRI/DWI; MRV; CTA
Fever with seizure Meningitis, encephalitis; chorioamnionitis CSF analysis; blood cultures; MRI
Seizure >6 weeks postpartum Late postpartum eclampsia possible but rare; consider CVT, epilepsy Full workup as new-onset seizure; MRV

6. MONITORING PARAMETERS

Parameter Frequency Target/Threshold Action if Abnormal ED HOSP OPD ICU
Blood pressure q5 min during acute treatment; q15 min x 2h; then q1h; q4h once stable <160/110 acute; <150/100 target range; <140/90 postpartum Persistent ≥160/110 → IV antihypertensive; resistant → ICU STAT STAT ROUTINE STAT
Magnesium level q4-6h during infusion; q6h maintenance; PRN if toxicity signs 4-7 mEq/L therapeutic <4 → increase rate; >7 → decrease rate/hold; >10 → stop + calcium gluconate STAT STAT - STAT
Deep tendon reflexes (patellar) q1h during MgSO4 infusion Present (2+) Absent/diminished → check Mg level; hold MgSO4 if areflexic; have calcium gluconate ready STAT STAT - STAT
Respiratory rate q1h during MgSO4 >12 breaths/min <12 → hold MgSO4; administer calcium gluconate; prepare for intubation STAT STAT - STAT
Urine output q1h (Foley catheter recommended) >25 mL/h (>0.5 mL/kg/h) <25 mL/h → reduce MgSO4 (renal excretion); assess volume status; oliguria → fluid bolus vs renal failure STAT STAT - STAT
Fetal heart rate Continuous during acute management 110-160 bpm; reactive Non-reassuring → OB assessment; emergent delivery if persistent fetal distress STAT STAT - STAT
CBC with platelets q6-12h if HELLP; daily if preeclampsia Platelets >100K; stable Hgb Falling platelets → worsening HELLP; Hgb drop → hemorrhage or hemolysis STAT STAT ROUTINE STAT
LFTs (AST/ALT) q6-12h if HELLP; daily if preeclampsia Trending down after delivery Rising → worsening HELLP; peak usually 24-48h after delivery then improve STAT STAT ROUTINE STAT
LDH and haptoglobin q12-24h if HELLP LDH trending down; haptoglobin rising Worsening → ongoing hemolysis; not improving 48-72h → consider TTP/aHUS - STAT - STAT
ASM levels (if epilepsy) At admission; monthly during pregnancy; 1 week postpartum Pre-pregnancy target level Subtherapeutic → increase dose; postpartum → reduce dose (levels rebound) STAT STAT ROUTINE STAT
Postpartum BP monitoring Daily x 72h inpatient; home monitoring daily x 6 weeks <140/90 Persistent hypertension → continue/escalate antihypertensives; new onset >48h → evaluate late postpartum preeclampsia - ROUTINE ROUTINE -

7. DISPOSITION CRITERIA

Disposition Criteria
Admit to ICU Eclamptic seizure; refractory hypertension (≥160/110 despite 2 IV agents); HELLP with platelets <50K or DIC; pulmonary edema; renal failure; persistent altered mental status; intubation
Admit to L&D / high-risk antepartum Severe preeclampsia with controlled BP; stable HELLP (platelets >50K); post-eclamptic seizure now stable; pending delivery planning
Discharge home (postpartum) Seizure-free ≥24h after MgSO4 completion; BP consistently <150/100 on oral agents; normalizing labs; oral medications tolerated; reliable follow-up arranged; home BP cuff provided
Outpatient follow-up Neurology 2-4 weeks (MRI review, recurrence risk); OB 1-2 weeks (BP, proteinuria); MFM before future pregnancy for risk counseling
Transfer to tertiary center If facility lacks MFM, NICU, or neurocritical care capabilities; HELLP with DIC; refractory status epilepticus in pregnancy

8. EVIDENCE & REFERENCES

Recommendation Evidence Level Source
Magnesium sulfate superior to phenytoin and diazepam for eclampsia prevention and treatment Class I, Level A (large RCTs) The Magpie Trial. Lancet 2002
MgSO4 reduces eclampsia risk by 58% compared to placebo in severe preeclampsia Class I, Level A Altman et al. BJOG 2002 (Magpie follow-up)
Labetalol and nifedipine equally effective for acute severe hypertension in pregnancy Class I (RCT) Shekhar et al. Pregnancy Hypertens 2016
PRES is the neuroimaging correlate of eclampsia in majority of cases Class III evidence (case series) Brewer et al. AJNR 2013
Low-dose aspirin 81 mg from 12-16 weeks reduces preeclampsia risk in high-risk women Class I, Level A Rolnik et al. NEJM 2017 (ASPRE trial)
Lamotrigine and levetiracetam preferred ASMs in pregnancy (lowest teratogenicity) Class II evidence; Registry data Tomson et al. Lancet Neurol 2018 (EURAP)
Lamotrigine levels decrease 50-70% during pregnancy; monthly monitoring needed Class II evidence Pennell et al. Neurology 2008
Delivery is definitive treatment for eclampsia; timing depends on gestational age and maternal/fetal status Guideline ACOG Practice Bulletin 222: Gestational Hypertension and Preeclampsia 2020
Postpartum eclampsia occurs in up to 26% of eclampsia cases; monitoring continues 48h post-delivery Class III evidence Al-Safi et al. Am J Obstet Gynecol 2011
CVT risk is 12x higher in pregnancy/postpartum; must be excluded in seizures with headache Class III evidence Ferro et al. Stroke 2004

CHANGE LOG

v1.0 (January 31, 2026) - Initial template creation - Comprehensive eclampsia/seizure in pregnancy management including MgSO4 protocols, PRES overlap, HELLP differentiation, ASM safety in pregnancy, and postpartum management


APPENDIX A: Magnesium Sulfate Toxicity Levels

Mg Level (mEq/L) Clinical Effect Action
1.5-2.5 Normal baseline No action
4-7 Therapeutic range (seizure prophylaxis) Maintain infusion; monitor reflexes q1h
7-10 Loss of patellar reflexes; warmth, flushing Hold infusion; recheck level q2h; resume at lower rate when <7
10-12 Respiratory depression; somnolence STOP infusion; calcium gluconate 1g IV; prepare for intubation
>12 Respiratory arrest; cardiac arrest STOP infusion; calcium gluconate 1g IV STAT; intubate; ACLS if cardiac arrest

APPENDIX B: ASM Safety in Pregnancy Quick Reference

ASM Pregnancy Category Major Malformation Rate Safe in Breastfeeding Key Risk
Lamotrigine PREFERRED 2-3% Yes Levels drop 50-70%; monthly monitoring
Levetiracetam PREFERRED 1-2% Yes Levels drop ~60%; renal dosing
Oxcarbazepine Acceptable 2-3% Yes Monitor sodium
Carbamazepine Caution 3-5% Yes NTD risk 0.5-1%; enzyme inducer
Topiramate AVOID 4-9% Yes Cleft lip/palate 3x risk
Valproate CONTRAINDICATED 9-11% Caution NTD 1-2%; IQ reduction; DO NOT USE
Phenytoin AVOID 3-7% Yes Fetal hydantoin syndrome
Phenobarbital AVOID 5-7% Caution Cardiac defects; cognitive effects
Lacosamide Insufficient data Unknown Probably yes Use with caution
Brivaracetam Insufficient data Unknown Unknown Use with caution