ABSTRACT INTRODUCTION The aim of this study was to investigate the effect of a lower dose subcutaneous sterile water injection technique versus subcutaneous saline injection, on the relief of low-back pain for women during childbirth, and to explore the lasting effects of pain relief after administration (followed at 15, 30, 45, 90 and 120 minutes). METHODS A prospective randomized controlled single-blinded study was conducted, with trial registration (NCT02813330). Women received one-time injections (sterile water or saline) and the effectiveness was observed at 15, 30, 45, 90 and 120 minutes after the intervention. RESULTS The intervention group had statistically significant pain reduction. Assessment of subsequent pain, followed at 30, 45, 90 and 120 minutes, reflected an increasing change with a statistically significant difference. The intervention group had more burning sensations than the control group with a statistically significant difference. CONCLUSIONS The modified technique of double injections of subcutaneous ‘water/ saline’ resulted in significant relief of low-back pain during childbirth.