Does magnesium sulfate work?
Despite its widespread use, there are few studies on magnesium sulfate’s use as a preterm labor drug. A 1997 review of published studies on magnesium sulfate found eight that met the reviewers’ criteria. Of this eight, two compared magnesium sulfate to no treatment or a placebo. The other six compared magnesium sulfate to another preterm labor drug (either ritodrine or terbutaline). The review of studies (Obstetrical and Gynecology Survey, Vol. 52, pp. 652-658) concluded that more research — with more test subjects — is needed. It said the two placebo-controlled or no treatment controlled studies appear to show magnesium sulfate has no benefit. But these two studies may have been skewed by an insufficient number of study subjects. In reviewing the six studies comparing magnesium sulfate to terbutaline or ritodrine, the review concluded that magnesium sulfate appears to be as effective as ritodrine or terbutaline in delaying delivery for 48 hours. However, because of the small number
