(1141) Eclampsia despite magnesium sulfate prophylaxis

Friday, February 10, 2023

3:30 PM – 5:00 PM

Objective: Intravenous magnesium sulfate (MgSO4) is highly effective in preventing eclamptic seizures when given to pregnant patients with preeclampsia with severe features or eclampsia. The consequences of developing eclampsia despite receiving MgSO4 prophylaxis have not been well established. The aim of this study was to determine characteristics and outcomes of patients with eclampsia despite MgSO4 therapy.

Study Design: This study included patients who delivered at our institution from January 2009 to December 2021 with a diagnosis of eclampsia. Serum magnesium concentrations were measured at 2, 4, and 12 hours after initiation of MgSO4 infusion in patients receiving MgSO4 for seizure prophylaxis. Characteristics and outcomes of patients developing eclampsia while receiving MgSO4 were then analyzed.

Results: Of 154,036 deliveries, 14,569 (9.5%) patients received MgSO4 for eclampsia prophylaxis or therapy. One-hundred and seven patients developed eclampsia (6.95 per 10,000 births), with seizures occurring following initiation of MgSO4 prophylaxis in 21 (20%) patients. Fifteen (71%) of the 21 patients developed eclampsia despite a therapeutic (4.8-8.4 mg/dL) serum magnesium concentration prior to the seizure. Another 3 had an eclamptic seizure associated with a sub-therapeutic level and 3 occurred prior to evaluation of serum magnesium concentration at 2 hours. Outcomes of these 21 patients were as follows: 6 (29%) had more than one eclamptic seizure on MgSO4, 3 (14%) were diagnosed with abruptio placentae, 7 (33%) underwent immediate intubation following the eclamptic seizure, 2 (10%) experienced aspiration pneumonia, and 5 (24%) required admission to the intensive care unit.

Conclusion: Magnesium sulfate is highly effective in preventing eclampsia. Although rare, one in five eclamptic seizures occurred despite prophylaxis, with 71% having a therapeutic serum magnesium concentration prior to the seizure. Patients experiencing eclampsia despite receiving prophylaxis experienced significant maternal morbidity.

Primary & Presenting Author(s)

Sara I. Jones, MD (she/her/hers)
University of Texas Southwestern Medical Center
Dallas, Texas, United States

Coauthor(s)

Rachel C. Schell, MD (she/her/hers)
University of Texas Southwestern Medical Center
Irving, Texas, United States
Anne M. Ambia, MD
Assistant Professor
University of Texas Southwestern Medical Center
Dallas, Texas, United States
CW
Chet Wells, MD
University of Texas Southwestern Medical Center
Dallas, Texas, United States
GC
Gary Cunningham, MD
UT Southwestern Medical Center
Dallas, Texas, United States