Water Injections

This is not commonly offered in most trusts, so if it’s something you’d like to try/have in your birth preferences you’ll need to talk to your care provider about it during pregnancy.

There has been some discussion in recent years around whether sub- or intra-cutaneous (under on in the middle of the skin layers) injections of sterile water across 4 sites in the lower back is an effective method of back pain relief during labour. This is also known as a “water block” as it works on the pain gate theory; that by irritating more surface-level pain receptors, deeper pain receptors in the back are blocked. Water injections seem to work in a similar way to a TENS machine, without the wires, and allow free movement and use of a birthing pool after the injections are done. The initial injection is experienced as a painful stinging sensation (NICE, 2023), with pain relieving effects lasting from 30-90 minutes on average where felt (ibid). However, the majority of evidence for the efficacy of sterile water injections comes from studies with inconsistent reporting of other influencing factors so is not generally of particularly high quality (ibid).  

It is mainly proposed as a useful pain management technique for women experiencing back pain in labour, but not recommended for general labour pain (“front labour”) as it does not show effectiveness for this (the research is focused on its prevention of back pain in labour only).  As back pain in labour tends to be caused by sub-optimal fetal positioning, this could potentially be better combated by taking steps to address this issue in labour, such as Spinning Babies techniques, rebozo shakes, movement and positioning adjustments.

However, where appropriate, and should you desire a less medicalised form of pain relief, sterile water injections could form a part of your birthing toolkit to support pain relief from back pain whilst exploring other adjustments to help this during labour.