Sterile wAter injecTions to relieve laboUR paiN (SATURN Trial)
Sterile water injections have been demonstrated to effectively manage back pain experienced during labour with no side effects other than the administration pain. Abdominal labour pain differs to back pain in location and likely physiological derivation. It was not known if sterile water injections would be efficacious in the relief of abdominal labour contraction pain.
We assessed the efficacy of sterile water injections to reduce abdominal labour contraction pain using a two-arm superiority randomised placebo-controlled trial. The study was conducted in a referral maternity hospital in Brisbane, Australia.
Methods: Between April 2022 and November 2023 consenting women in spontaneous or induced labour at term requesting analgesia were assigned (1:1) by an independently generated randomisation schedule to injections of either sterile water or saline placebo. The primary outcome was the difference between groups in self-reported visual analogue pain score at 30 min following allocated treatment. Secondary outcomes included use of pharmacologic analgesia following allocation. Analysis was by intention to treat.
160 women were randomised to sterile water injections (n = 81) or injections of saline placebo (n = 79).
Sterile water injections provided a statistically significant reduction in pain when compared to a placebo for up to 60 min following treatment. However, the use of other pharmacological analgesia such as epidural did not differ between groups.
Trial registration: The trial is registered at the Australian and New Zealand Clinical Trials Registry (Trial ID: ACTRN12621001036808). Registration date 5/08/2021. First recruitment 29th April 2022.
Lee, et al. Sterile water injections for relief of labour pain (the SATURN trial): study protocol for a randomised controlled trial. Trials. 2022;23(1):155. https://doi.org/10.1186/s13063-022-06093-3.
Lee N, Martensson LB, Gao Y, Callaway L, Barnett B, Hellyer S, Kearney L, Kildea S. Sterile water injections for managing abdominal labour contraction pain: a randomised double blind placebo-controlled trial. International Journal of Nursing Studies. 2025 Oct 3 https://doi.org/10.1016/j.ijnurstu.2025.105244
Lee, N., Barnett, B., Kildea, S. et al. A qualitative study of clinicians’ perspectives on participating in an intrapartum randomised placebo-controlled trial for labour pain relief. Trials 26, 547 (2025). https://doi.org/10.1186/s13063-025-09257-z
Project members
UQ investigators
- Professor Leonie Callaway
External investigators
- Ms Sarah Kirby (Royal Brisbane and Women’s Hospital)
- Mrs Patricia Smith (Royal Brisbane and Women’s Hospital)
- Ms Janine Farquharson (Royal Brisbane and Women’s Hospital)
- Dr Akwasi Amoako (Royal Brisbane and Women’s Hospital)
Partner organisations
- Royal Brisbane and Women's Hospital