Intravenous magnesium sulfate may relieve restless legs syndrome in pregnancy.

We report a case of restless legs syndrome that improved after intravenous magnesium sulfate administration. A 34-year-old gravida 1 para 0 woman, with a 13-year history of restless legs syndrome, was prescribed bed rest due to pre-term labor at 26 weeks. While at rest, the subject experienced severe restless legs syndrome.