In pregnancies less than 32 weeks gestation, which intervention provides neuroprotection to the fetus?

• A. Corticosteroids for fetal lung maturation
• B. Antibiotics for GBS
• C. Magnesium sulfate for neuroprotection
• D. Tocolytics to reduce contractions

Answer: (C)

Magnesium sulfate given to the mother when preterm birth is anticipated provides fetal neuroprotection. It lowers the risk of cerebral palsy and severe neurodevelopmental impairment in infants born before 32 weeks. The protective effect is thought to arise from magnesium acting as a CNS stabilizer, antagonizing NMDA receptors and reducing excitotoxic neuronal injury during hypoxic-ischemic stress around birth. While corticosteroids help with fetal lung maturation and antibiotics prevent infection, the specific neuroprotective benefit in this gestational window is achieved with maternal magnesium sulfate. Tocolytics delay birth but do not provide direct neuroprotection.