What is the role of magnesium sulfate in obstetric care?

• A. Oral sedation for labor
• B. Seizure prophylaxis in preeclampsia with severe features or eclampsia, and fetal neuroprotection when preterm delivery is anticipated before 32 weeks
• C. Prevents bacterial infection
• D. Treats anemia

Answer: (B)

Magnesium sulfate is used in obstetric care mainly as an anticonvulsant for the mother and as a neuroprotective measure for the fetus. It helps prevent seizures in preeclampsia with severe features and in eclampsia by reducing neuronal excitability and stabilizing the central nervous system. It also provides fetal protection when early delivery is anticipated before 32 weeks, reducing the risk of cerebral palsy and other neurological injury in the newborn. It is not given as an oral sedative for labor, nor does it prevent bacterial infection or treat maternal anemia. For safety, therapy requires monitoring of reflexes, respiratory rate, and urine output, and toxicity is treated with calcium gluconate if it occurs.