12 versus 24 hours of postpartum magnesium sulfate for seizure prophylaxis: A cost-effectiveness analysis

The approach to prevent eclampsia in the postpartum period utilizes magnesium sulfate but there is no evidence-based standard to guide duration.

To assess the cost-effectiveness of an abbreviated 12-hour postpartum magnesium sulfate regimen compared with a standard 24-hour regimen.

A decision-analytic model was constructed to compare a 12-hour regimen with a 24-hour regimen in a theoretical cohort of 45,800 patients with preeclampsia with severe features. Probabilities, costs, and utilities were derived from the literature. Primary outcomes included incremental cost per quality-adjusted life-year (QALY), cases of eclampsia, magnesium toxicity, and maternal death. The cost-effectiveness threshold was $100,000 per QALY.

A 12-hour regimen in this theoretical cohort of 45,800 postpartum patients compared with a 24-hour regimen resulted in 86 more cases of eclampsia (398 vs 312) and 0.37 more deaths (10.87 vs 10.50). However, there were 656 fewer cases of magnesium toxicity (2089 vs 2745). Overall, a 12-hour regimen was a dominant strategy that resulted in decreased costs of $21.5 million and increased effectiveness of 17 QALYs.

In our study, an abbreviated duration of postpartum magnesium sulfate prophylaxis for patients with preeclampsia with severe features was a dominant strategy (lower costs, better outcomes) and cost-effective compared with the standard 24-hour regimen.