 Results: Ninety-nine women completed the study without any maternal adverse effects. The mean increase in amniotic fluid index after hydration was significantly greater in the isotonic solution and water groups 12.1mm, p0.02; 13.1mm, p0.05; respectively than the control group 1.4mm, p0.74. There was no significant difference between the isotonic solution and water groups. Hydration with isotonic solution and water improved the chance of 20 of increase of amniotic fluid index in 10.2 95 CI 1.9-98.9 and 6.0 95 CI 1.0-45.5 times respectively. 