What Is Magnesium Sulfate, and How Might It Help Prevent Preterm Birth and HIE?
Magnesium sulfate (along with betamethasone) should be administered to a baby about to be born preterm (24-32 weeks) in order to protect against cerebral palsy. While the baby is still in utero, the mother receives magnesium sulfate, which helps increase blood flow to the baby’s brain, decrease the levels of inflammatory molecules in the brain that can cause damage, reduces excitotoxicity, stabilizes cell membranes and prevents large blood pressure changes that can cause brain damage.
Medical personnel administer magnesium sulfate to women about to give birth to a premature baby within 24 hours whether or not their membranes have ruptured preterm. Generally, they begin with a 4g dose via IV and provide 1g of a maintenance dose every hour for 24 hours or until the baby is born (whichever is sooner). If it is likely labor will take more than 24 hours, doctors should hold off on beginning magnesium sulfate therapy until closer to the time of delivery. However, if the baby is not doing well and needs to be delivered immediately, doctors should not delay delivery to finish providing magnesium sulfate.
Magnesium sulfate isn’t for every pregnancy, however. Women with certain neuromuscular diseases or heart or kidney issues should be very carefully evaluated to prevent magnesium toxicity and should be very carefully monitored. If doctors are using a tocolytic to prevent preterm labor in conjunction with magnesium sulfate, the kind of tocolytic they should use is indomethacin.