LandmarkRCT

Magpie

Do Women with Pre-eclampsia, and Their Babies, Benefit from Magnesium Sulphate? The Magpie Trial: A Randomised Placebo-Controlled Trial

Lancet, 2002 · International, multicenter, randomized, double-blind, placebo-controlled trial

Clinical question

Does magnesium sulfate prevent eclamptic seizures and reduce maternal/fetal mortality in women with preeclampsia?

Population: 10,141 pregnant or postpartum women with preeclampsia across 33 countries
Intervention: Intravenous/intramuscular magnesium sulfate regimen (n = 5071)
Comparator: Matching placebo infusion (n = 5070)
Primary outcome: Occurrence of eclampsia and maternal/perinatal death
Result: Magnesium sulfate reduced the risk of eclampsia by 58% (0.8% vs 1.9%, RR 0.42, 95% CI 0.29–0.60, P < 0.0001) and significantly reduced maternal mortality (RR 0.55, 95% CI 0.26–1.14), with NNT of 63 in severe preeclampsia. (RR 0.42 (95% CI 0.29–0.60), <0.0001)

What the trial found

Magnesium sulfate dramatically halves the incidence of eclampsia in preeclampsia without significant maternal or fetal harm.

Current guideline position

ACOG, WHO, and SMFM strongly recommend magnesium sulfate for seizure prophylaxis and treatment in preeclampsia with severe features and eclampsia.

Clinical interpretation

Definitive landmark trial establishing magnesium sulfate as the global standard of care for seizure prophylaxis and treatment in preeclampsia with severe features.

High certainty

Clinical Context & Relevant Topics (3)

Disease Reference

Obstetric Critical Care

Maternal physiology, preeclampsia/eclampsia, HELLP vs AFLP, postpartum hemorrhage (MTP/TXA), peripartum cardiomyopathy, and arrest.

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Status Epilepticus

Recognition and time-sensitive escalation of care for prolonged or repeated seizures.

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Hypertensive Emergencies

Target organ damage assessment, intravenous antihypertensive titration, and emergency-specific blood pressure targets.

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