Magnesium sulfate for the prevention of seizures in preeclampsia: origin, experimental basis, clinical studies, and the evolution in obstetrical practice.

For centuries, convulsions unique to pregnancy have been described. In this time, varying therapies-from phlebotomy to narcotics-have been suggested as the treatment of choice for eclampsia. Building upon the discovery of magnesium salts to control convulsions due to tetanus, magnesium sulfate became a suggested treatment for eclampsia. Throughout the 20th century, several large, clinical trials verified magnesium sulfate as the treatment of choice for eclampsia. In this report, the history of eclampsia management and the study of magnesium sulfate are described. The intent of the report is to highlight the key clinical features with use of magnesium sulfate, the present understanding of the mechanism of action, and the rigor of the studies by which it was established as the current definitive prophylaxis and therapy for eclampsia. Because of the unique pharmacologic properties, it is critical that obstetric providers understand the foundational studies to establish dosing and identified risks with magnesium sulfate application. Additionally, alleged putative effects of magnesium sulfate administration, such as prolongation of labor, are also addressed. Lastly, the challenges with use of magnesium sulfate in the prevention of eclampsia is summarized given the varying definitions of preeclampsia. This report serves as a chronicle to summarize the story of how one of the most commonly utilized agents in obstetrics became the standard of present-day care.