Abstract
Objective To evaluate the tolerability and safety of intravenous magnesium sulfate use for
tocolysis in a center that uses a “high-dose” regimen.
Study Design We conducted a retrospective cohort study of patients treated with magnesium sulfate
for preterm labor from December 2006 to June 2010. Data were abstracted from review
of individual patient electronic medical records.
Results The cohort consisted of 456 women. Of these, 417 (91.4%) experienced side effects.
Severe side effects (pulmonary edema, respiratory arrest, intensive care unit transfer,
cardiac arrest, or death) occurred in 24 (5.3%) cases, all but one due to pulmonary
edema. No cases of respiratory arrest, cardiac arrest, or death occurred. Those with
severe side effects were less likely to have a singleton and more likely to have a
higher order multifetal gestation (p < 0.001), received more magnesium, and more often were given multiple concurrent
tocolytics (p = 0.04).
Conclusion “High-dose” magnesium tocolysis results in side effects for 9 of every 10 patients
treated, and severe side effects occur in 1 of every 20 patients. When used for tocolysis,
magnesium should be used as a single agent, for less than 48 hours, and with great
caution in multifetal gestations.
Keyword
High-dose magnesium side effects
