Comparative evaluation of normal saline, 1/3-2/3, and ringer's lactate infusion on labour outcome, PH, bilirubin, and glucose level of the umbilical cord blood in nulliparous women with labour induction: a randomised clinical trial

This study aimed to compare the effects of infusion of normal saline, 1/3-2/3, and Ringer's lactate fluids on labour outcome, pH, bilirubin, and glucose level of umbilical cord blood. In this randomised clinical trial, 450 nulliparous women with Bishop score ˂5 and indication of pregnancy termination were randomly divided into three groups to receive normal saline, 1/3-2/3, or Ringer's lactate infusion at a rate of 125 mL/h for hydration, upon starting induction of labour. Results of this study indicated that the incidence of hypoglycaemia (p = .19), hyper bilirubinemia (p = .87) and acidosis (p = .10) was similar in neonates of the three groups. Also, there were no statistically significant differences between the three groups with regard to the duration of labour; glucose, bilirubin and pH level of cord blood; and mode of delivery. It can be concluded that infusion of Ringer's lactate, normal saline or 1/3-2/3 fluid during labour is not associated with different maternal or foetal/neonatal outcomes, and none of the fluids has superiority to the others.Impact statementWhat is already known on this subject? Several studies have been conducted on the association between type and volume of infused fluid on labour duration and neonatal outcomes. However, there has been some controversy.What do the results of this study add? This is the first study that has investigated the association between infusion of Ringer's lactate, normal saline or 1/3-2/3 fluid during labour with labour outcome and pH, bilirubin, and glucose level of the umbilical cord blood and results showed that these fluids have no effect on maternal or foetal/neonatal outcomes and also none of these fluids has superiority to the others.What are the implications of these findings for clinical practice and/or further research? Due to contradictory results of previous studies, further research with greater sample sizes and different fluids type and volumes may be needed to examine the association between infusion of fluids and neonatal and labour outcomes more precisely.