The outcomes reported severely limit conclusions for clinical practice. We found little robust evidence that sterile water is effective for low back or any other labour pain. Neither did we find any difference in delivery or other maternal or fetal outcomes. Further large, methodologically rigorous studies are required to determine the efficacy of sterile water to relieve pain in labour.
Relief of low back labor pain by using intracutaneous injections of sterile water: a randomized clinical trial.
To study the effectiveness of intracutaneous injections of sterile water in relieving low back pain during labor in Thai women.
                Randomized controlled trial.
                Department of Obstetrics and Gynecology, Taksin Hospital, Bangkok.
                Fifty pregnant women at term, requiring pain relief for severe low back pain during the first stage of labor. The women were randomized to receive either 4 intracutaneous injections of 0.1 mL sterile water (n = 25) or isotonic saline as placebo (n = 25).
                Pain scores measured by visual analogue scale.
                Mean pain scores were significantly lower among the treatment group compared to the placebo group at 30 minutes, 1 and 2 hours after injections (p = 0.018, 0.046, and 0.027 respectively). Mean pain reduction were significantly greater in the treatment group compared to the placebo group at 30 minutes, 1 and 2 hours after injections (p < 0.001). There was no difference between the two groups with regard to time to delivery and rate of instrumental and cesarean delivery.
                The intracutaneous injections of sterile water was found to be an effective treatment against lower back pain during the first stage of labor.