Eclampsia or severe preeclampsia: pregnant or after birth
Seizure, BP 160/110 mmHg or more, or preeclampsia with a severe feature, from 20 weeks of pregnancy until after birth. Adult doses.
All Pathways
Obstetrics & GynecologyEmergency
Eclampsia & Severe Preeclampsia Management (ACOG 2020, SOMANZ 2023)
Eclampsia & Severe Preeclampsia Management (ACOG 2020, SOMANZ 2023): Eclampsia or severe preeclampsia: pregnant or after birth → Eclamptic seizure now, ...
Pathway Overview
21 steps
Algorithm Steps
21 total
01Start 02Decision Eclamptic seizure now, or at any time before or since arrival?
A seizure in this pregnancy or after birth, with no other clear cause, is eclampsia even if BP is not severe. Yes: eclampsia steps. No: check for severe features.
- If Yes
03Action Eclampsia: call for help, protect the airway, left lateral
Give magnesium sulfate as the first anticonvulsant (next step). Do not use diazepam or phenytoin instead of magnesium. Unit without obstetric or intensive care: arrange urgent transfer once stable.
- Call obstetric, anaesthetic and midwifery emergency help
- Left lateral position; protect from injury; do not restrain
- Clear and support the airway; give oxygen; monitor SpO2
- Insert 2 large-bore IV cannulas; check blood glucose
- Stabilise the mother before any decision on birth; fetal heart rate changes during a seizure often recover
- Atypical seizure (focal signs, before 20 weeks, seizure despite magnesium, slow recovery): urgent brain imaging and look for other causes
04Action Eclampsia: magnesium sulfate 4 g IV load, then 1 g/hour
Renal impairment or oliguria: reduce the infusion by 50% and check serum magnesium. Myasthenia gravis: do not give magnesium; get senior advice.
- Load: magnesium sulfate 4 g IV over 20 min (adult). No IV access: 10 g IM (5 g into each buttock) and arrange transfer
- Then magnesium sulfate 1 g/hour IV (no IV access: 5 g IM every 4 h into alternate buttocks, only if reflexes present, RR more than 12/min and urine at least 100 mL in 4 h) until 24 h after birth or after the last seizure, whichever is later
- Recurrent seizure: magnesium sulfate 2-4 g IV over 5-15 min
- Prolonged seizure despite magnesium: diazepam 5-10 mg IV or midazolam 5-10 mg IV or IM; support the airway
05Warning Magnesium: check for toxicity; limit IV fluids to 80 mL/hour
Limit total IV fluids to 80 mL/hour unless there are other losses (for example haemorrhage). Measure serum magnesium only if renal impairment or signs of toxicity.
- Every 30 min: BP, HR, RR, SpO2. Every hour: reflexes and urine output
- Absent reflexes, RR 12/min or less, drowsiness or slurred speech: stop the infusion and check serum magnesium
- Toxicity (clinical signs or magnesium more than 3.5 mmol/L): calcium gluconate 10% 10 mL in 100 mL sodium chloride 0.9% IV over 10 min
06Decision BP 160/110 mmHg or more (confirmed within 15 min)?
Yes: give a short-acting antihypertensive now. No: keep checking BP and go to the next step (birth or after-birth care).
- If Yes
07Action BP 160/110 or more: give a short-acting antihypertensive now
Aim for BP below 160/110 mmHg; individualise if the fetus is compromised. Asthma, heart failure, heart block or bradycardia: do not use labetalol. Aortic stenosis: avoid nifedipine; use IV labetalol or hydralazine.
- Nifedipine immediate-release 10-20 mg oral every 30 min, max 45 mg
- Or labetalol 20-40 mg IV every 10-15 min, max 80 mg
- Or hydralazine 5-10 mg IV every 20 min, max 30 mg; consider 250 mL sodium chloride 0.9% first (not if pulmonary edema)
- Or diazoxide 15 mg IV every 5-10 min, max 300 mg (Australia); stop when BP is at target (risk of hypotension)
- BP every 10-15 min and continuous CTG during treatment
- Still 160/110 or more: labetalol infusion 20-160 mg/hour or hydralazine infusion 10-20 mg/hour, with senior and ICU input
- Also start or increase oral antihypertensives to prevent a rebound
08Decision Has she already given birth?
Yes (after birth): check for HELLP, then after-birth care. No (still pregnant): decide timing of birth by gestation.
- If Yes
09Decision HELLP syndrome?
HELLP: haemolysis, AST or ALT more than 2 x normal, and platelets less than 100 x 10^9/L (criteria below). It can occur without severe hypertension and after birth.
- Haemolysis: LDH 600 IU/L or more, schistocytes on the film, or bilirubin more than 20 umol/L (1.2 mg/dL)
- AST or ALT more than 2 x upper limit of normal
- Platelets less than 100 x 10^9/L
- If Yes
10Action HELLP: stabilise, birth if still pregnant; watch for bleeding and liver rupture
Birth is the definitive treatment. Do not give corticosteroids to treat HELLP (steroids for fetal lung maturity only).
- Check platelets and coagulation before birth and before neuraxial anaesthesia
- Platelet transfusion and blood products with anaesthesia and haematology advice
- RUQ or shoulder pain, or shock: suspect liver haematoma or rupture; urgent imaging and surgical review
- Repeat FBC, LFTs, LDH and coagulation until they improve
11Action After birth: magnesium for 24 h and close BP checks
Eclampsia, severe hypertension and HELLP can first occur after birth. Avoid NSAIDs for pain if other analgesics work.
- Continue magnesium until 24 h after birth or the last seizure, whichever is later; if started after birth, for 24 h
- Check BP at least 4 times a day in hospital; ask about severe headache and epigastric pain each time
- Start or continue antihypertensives if BP is 150/100 mmHg or more; 160/110 or more: treat now
- Pulmonary edema or fluid overload: consider a loop diuretic
12Outcome Discharge and follow-up
Review within 1 week of discharge; severe hypertension: BP check within 3 days (72 h). Explain the long-term cardiovascular risk. Next pregnancy: early review and aspirin before 16 weeks.
If No- Path rejoins step 11Shared downstream outcome
If No13Decision Still pregnant: gestation 34 weeks or more?
Yes: plan birth after stabilisation. No (less than 34 weeks): steroids, transfer and assess for expectant care.
- If Yes
14Action 34 weeks or more: plan birth after the mother is stable
Birth is recommended for preeclampsia with severe features at 34 weeks or more.
- Control BP and start magnesium first
- Choose mode of birth by obstetric factors and the woman's preference
- Caesarean for urgent maternal or fetal indications
- Continue magnesium during birth and for 24 h after
- Check platelets and coagulation before neuraxial anaesthesia
- Path rejoins step 09Shared downstream outcome
If No15Action Less than 34 weeks: steroids, stabilise, transfer
Transfer to a unit with maternal and neonatal intensive care if it is safe to move. Before 24 weeks: senior obstetric and neonatal counselling before steroids or expectant care.
- Betamethasone 11.4 mg IM, 2 doses 24 h apart (Australia; 12 mg in the US)
- Control BP; continue magnesium while she is assessed for expectant care
- Repeat FBC, creatinine and LFTs; frequent fetal monitoring
- Birth likely before 30 weeks: continue magnesium for fetal neuroprotection
16Decision Less than 34 weeks: deterioration or another indication for birth?
Yes to any (for example eclampsia, stroke, severe BP despite 2 drugs, pulmonary edema, platelets less than 50 x 10^9/L, HELLP, abruption, fetal compromise): plan birth at any gestation. No: expectant care.
- Eclampsia, severe headache, repeated visual scotomata, stroke or altered consciousness
- Severe BP again despite 2 or more antihypertensives
- Pulmonary edema
- Platelets falling or less than 50 x 10^9/L, or DIC
- Creatinine more than 90 umol/L and rising, liver enzymes rising, HELLP, or liver rupture
- Placental abruption with maternal or fetal compromise
- Non-reassuring fetal status or fetal death
- If Yes
17Action Deterioration at any gestation: plan birth after stabilisation
Do not delay birth to complete the steroid course.
- Control BP and continue magnesium
- Give steroids if less than 34 weeks and there is time, but do not wait for them
- Choose mode of birth by obstetric factors
- Continue magnesium for 24 h after birth
- Path rejoins step 09Shared downstream outcome
If No18Action Stable, less than 34 weeks: expectant care in a tertiary unit
Only where maternal and neonatal intensive care is available. Stop magnesium once expectant care is chosen; restart it when birth is planned or labour starts. Reassess the mother and fetus at least daily.
- Regular BP, symptoms, FBC, creatinine, LFTs and fetal wellbeing
- Any deterioration: restart magnesium and plan birth at any gestation
- Still stable at 34 weeks: plan birth
- Path rejoins step 14Shared downstream outcome
If No- Path rejoins step 08Shared downstream outcome
If No19Decision Preeclampsia with any severe feature?
Yes to any one: BP 160/110 mmHg or more; platelets less than 100 x 10^9/L; AST or ALT more than 2 x normal, or severe RUQ pain; raised creatinine; pulmonary edema; new headache or visual disturbance. Treat severe BP (confirmed within 15 min) now; do not wait 4 hours.
- SBP 160 mmHg or more, or DBP 110 mmHg or more (confirm within 15 min)
- Platelets less than 100 x 10^9/L
- AST or ALT more than 2 x upper limit of normal, or severe persistent RUQ or epigastric pain
- Creatinine more than 1.1 mg/dL (97 umol/L), or doubled
- Pulmonary edema
- New headache not relieved by medicine, or visual disturbance
- If Yes
20Action Severe features: magnesium sulfate 4 g IV load, then 1 g/hour
Prevents eclampsia. Renal impairment or oliguria: reduce the infusion by 50% and check serum magnesium. Myasthenia gravis: do not give magnesium; get senior advice. Expectant care chosen before 34 weeks: stop magnesium and restart it for birth.
- Load: magnesium sulfate 4 g IV over 20 min (adult). No IV access: 10 g IM (5 g into each buttock) and arrange transfer
- Then magnesium sulfate 1 g/hour IV (no IV access: 5 g IM every 4 h into alternate buttocks, only if reflexes present, RR more than 12/min and urine at least 100 mL in 4 h) until 24 h after birth; if started after birth, for 24 h
- Seizure despite magnesium: treat as eclampsia; magnesium sulfate 2-4 g IV over 5-15 min
- Birth likely before 30 weeks: magnesium also gives fetal neuroprotection
- Path rejoins step 05Shared downstream outcome
If No21Outcome No severe feature: preeclampsia without severe features
Admit or review as per local care. Oral labetalol, nifedipine or methyldopa for BP control. Still pregnant: plan birth at 37 weeks, or earlier if the mother or fetus deteriorates. Reassess for severe features at every review and return to this pathway if one appears.
Guideline Source
ACOG Practice Bulletin No. 222: Gestational Hypertension and Preeclampsia
Clinical Safety Information
Clinical Decision Support — Not a Substitute for Clinical Judgment
Individual patient factors may require deviation from these recommendations.
Known Limitations
- Drug doses follow SOMANZ 2023 (Australia/NZ); ACOG 2020 allows higher cumulative labetalol doses - follow local protocol
- Adult doses; not for seizures with another likely cause (focal signs, before 20 weeks)
- Does not cover chronic hypertension or preeclampsia without severe features in detail
- HELLP and liver haematoma need specialist obstetric, anaesthetic and haematology care
Contraindicated Populations
Not pregnant and not postpartumChildren (paediatric doses not given)
Applicable Regions
AUNZUSEUGlobal
AU: Doses follow SOMANZ Hypertension in Pregnancy Guideline 2023. Betamethasone (Celestone Chronodose) 11.4 mg IM, 2 doses 24 h apart. IV nicardipine is not on the ARTG. IV labetalol and immediate-release nifedipine supply may be limited; IV diazoxide is an option.
UK: NICE NG133: magnesium 4 g IV over 5-15 min then 1 g/hour for 24 h; recurrent seizure 2-4 g IV.
US: ACOG Practice Bulletin 222 (reaffirmed 2026). ACOG escalates IV labetalol 20, 40 then 80 mg with a higher cumulative maximum than SOMANZ; follow local protocol. Betamethasone 12 mg IM x2.
Version 2Next review: 2027-09-30
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Frequently Asked Questions
What is the Eclampsia & Severe Preeclampsia Management (ACOG 2020, SOMANZ 2023)?
The Eclampsia & Severe Preeclampsia Management (ACOG 2020, SOMANZ 2023) is a emergency clinical algorithm for Obstetrics & Gynecology. It provides a structured decision tree to guide clinical decision-making, based on ACOG Practice Bulletin No. 222: Gestational Hypertension and Preeclampsia.
What guideline is the Eclampsia & Severe Preeclampsia Management (ACOG 2020, SOMANZ 2023) based on?
This algorithm is based on ACOG Practice Bulletin No. 222: Gestational Hypertension and Preeclampsia (DOI: 10.1097/AOG.0000000000003891).
What are the limitations of the Eclampsia & Severe Preeclampsia Management (ACOG 2020, SOMANZ 2023)?
Known limitations include: Drug doses follow SOMANZ 2023 (Australia/NZ); ACOG 2020 allows higher cumulative labetalol doses - follow local protocol; Adult doses; not for seizures with another likely cause (focal signs, before 20 weeks); Does not cover chronic hypertension or preeclampsia without severe features in detail; HELLP and liver haematoma need specialist obstetric, anaesthetic and haematology care. Individual patient factors may require deviation from these recommendations.
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