Magnesium sulfate (MgSO4) is primarily used in the management of preeclampsia to prevent seizures. Preeclampsia is a condition characterized by high blood pressure during pregnancy, which can lead to eclampsia, a severe complication involving seizures. MgSO4 acts as an anticonvulsant by depressing the central nervous system to reduce the risk of seizures. It is not typically used for the prevention of uterine contractions, sedation, or fetal lung protection.