What condition does magnesium sulfate primarily treat in obstetric care?

Magnesium sulfate is primarily used in obstetric care to manage conditions such as preeclampsia. This medication acts as both an anticonvulsant and a vasodilator, which is essential in controlling severe hypertension and preventing seizures in pregnant individuals with preeclampsia. The administration of magnesium sulfate helps stabilize blood pressure and protects against the development of eclampsia, which is characterized by seizure activity.

In the context of the conditions listed, eclampsia is indeed treated with magnesium sulfate, but it is specifically used primarily to manage preeclampsia to prevent its progression to eclampsia. This distinguishes it as a first-line treatment for preeclampsia, making the connection clear as to why magnesium sulfate is critical in this scenario.