a prospective, randomized, controlled trial of high and low doses of magnesium sulfate for acute tocolysis

at the present, many drugs are used for inhibition of uterine contractions, but the proportions of preterm labors are increasing. although magnesium sulfate is the most commonly prescribed parenteral tocolytic agent, but its optimal use has yet to be delineated. in this study a high-dose protocol for magnesium sulfate tocolytic therapy was compared with a low-dose regimen. one-hundred patients admitted to the labor unit of imam reza&apos;s hospital with preterm labor were enrolled in the trial. the median times to successful tocolysis were 8 hours in the low-dose group and 4 hours in the high-dose group (p<0.001). patients treated with higher doses were also more likely to spend significantly less time in the labor and delivery unit (p<0.001). the median gestational age at delivery was 33 weeks in the low-dose group and 36 weeks in the high-dose group (p=o.oo l). there were not any statistically significant differences between the two groups with respect to pre- and post magnesium infusion side effects. these results suggest that in the high-dose group, tocolysis was achieved more rapidly and patients required shorter admissions to the labor and delivery unit without increased maternal or neonatal morbidity.