The MAGPIE trial (2002) established the role of magnesium sulfate in pre-eclampsia. Based on this trial, what is the number needed to treat (NNT) with magnesium sulfate to prevent one eclamptic seizure in women with pre-eclampsia?

• A Approximately 50
• B Approximately 200
• C Approximately 400
• D Approximately 100 ✓

Explanation

The MAGPIE trial enrolled over 10,000 women with pre-eclampsia and showed that magnesium sulfate reduced the risk of eclampsia by 58% compared to placebo. The absolute risk reduction was about 1% (from 1.6% to 0.8%), yielding an NNT of approximately 100 to prevent one eclamptic seizure. The trial also showed reduced risk of maternal death. Despite the relatively high NNT, magnesium sulfate is universally recommended in severe pre-eclampsia given the severity of eclampsia and its low cost. This landmark trial forms the basis for current universal magnesium prophylaxis guidelines.

Reference: Williams Obstetrics, 26th ed.

High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP

Written and medically reviewed by the StethoPrep medical team.