Magnesium Sulphate for Preterm Birth (MASP Study)

Magnesium sulphate will be given as a loading dose of 5 g infused for 20-30 minutes, followed by a maintenance dose of 1 g per hour. Placebo will be given in identical appearing doses. The maintenance infusion will be continued until delivery appears, or for 24 hours if delivery does not occur or no longer is considered imminent. The infusion will be resumed when delivery is considered imminent again. Another loading dose of 5 g will be given if at least 6 hours has passed after infusion was stopped. The doses that are used in this project are similar to those used for prevention of eclampsia among women with severe preeclampsia.