Maternal paralytic ileus as a complication of magnesium sulfate tocolysis

Beta-adrenergic agonists tocolysis is currently the most popular treatment modality in the United States. However, magnesium sulfate is receiving increasing attention as an alternating tocolytic agent in the presence of various clinical situations, such as the treatment of insulin-dependent diabetes. While there is an abundance of information about the maternal and fetal side effects associated with beta-adrenergic tocolysis, little information is available about maternal adverse side effects of magnesium sulfate treatment for preterm labor. Side effects such as pulmonary edema, respiratory depression, hypocalcemia, and hypermagnesemia have been reported in patients receiving this agent for either tocolysis or pre-eclampsia, though their occurrence is quite rare. One of the infrequent complications of beta-adrenergic agonist tocolysis is the occurrence of a paralytic ileus, which to our knowledge has not yet been reported in association with magnesium sulfate tocolysis. This article therefore concerns the development of a paralytic ileus in a patient receiving parenteral magnesium sulfate for tocolysis. The clinical features are described and the possible mechanisms involved discussed.