A Cochrane review included 2 studies with a total of 228 women with preterm labour and intact membranes, which compared intravenous hydration with bed rest alone. Risk of preterm delivery, before 37 weeks, (RR 1.09 ,95% CI 0.71 to1.68), before 34 weeks (RR 0.72, 95% CI 0.20 to 2.56) or before 32 weeks (RR 0.76, 95% CI 0.29 to 1.97), was similar between groups. Admission to neonatal intensive care unit occurred with similar frequency in both groups (RR 0.99, 95% CI 0.46 to 2.16).
Comment: The quality of evidence is downgraded by sparse data and indirectness of evidence. The number of participants is too small to assess the impact on substantive outcomes such as perinatal morbidity and mortality.