What is the primary purpose of administering intravenous magnesium sulfate in patients with preeclampsia?

The primary purpose of administering intravenous magnesium sulfate in patients with preeclampsia is to prevent convulsions, which are a serious complication that can occur in this condition, specifically in the form of eclampsia. Magnesium sulfate acts as a central nervous system depressant, which helps to stabilize neuronal excitability and reduces the risk of seizure activity.

In the setting of preeclampsia, the development of new-onset seizures indicates a progression to eclampsia, making magnesium sulfate critical in managing the condition and protecting maternal and fetal well-being. It has been established as a standard of care in this context and has been shown to be effective in reducing the incidence of seizures in women with preeclampsia.

While magnesium sulfate does have some effect on blood pressure due to its vasodilatory properties, its primary and most critical role remains the prevention of convulsions. Additionally, it does not reverse proteinuria or directly prevent HELLP syndrome, although managing preeclampsia could theoretically limit the risk of such complications.