Study	Reason for exclusion
Brun 2011	The main objective was to compare bed‐rest exercise (muscle‐conditioning exercises such as technique, breathing, perceived exertion) versus bed rest plus music. Since both arms considered bed rest ‐hospitalized for activity restriction ‐ the study was excluded.
Larsen 1980	The main objective was to evaluate ritodrine for preventing preterm birth. The compared interventions were ritrodrine and bed rest versus bed rest alone.
Latorre 2014	The main objective was to compare ambulatory management with hospitalized management of pregnant women with threatened preterm labor and cervical length > 25 mm. In both arms (ambulatory and hospitalized management) bed rest was included.
Ma 1992	The main objective was to evaluate the efficacy of magnesium sulfate in the treatment of preterm labour. The authors compared magnesium sulfate versus barbiturates, salbutamol sulfate or bed rest.