Impact on Caesarean Rates following Injections of Sterile Water (ICARIS) – A randomised controlled trial.

INTERVENTION: Women with back pain during first stage labour, assessed by visual analogue scale as = 7 will receive 0.1 – 0.3 millilitres of sterile water for injection. The exact volume injected is determined by visualisation of the resulting blister or bleb by the administering clinician. The injection is given using of one‐millilitre syringes and 23 gauge needles, one injection into four anatomical points surrounding the Michaelis rhomboid over the sacral area: two over the posterior superior iliac spines (PSIS) and the remaining two at two centimetres posterior, and one centimetre medial, to the PSIS respectively. Women may receive repeat injections upon request once the VAS is again = 7. Repeat injections will be of Sterile Water for injection. There is no maximum amount of injections that women may receive during their labour. CONDITION: Labour and birth PRIMARY OUTCOME: Caesarean Section SECONDARY OUTCOME: Fetal position prior to administration of intervention or placebo determined by abdominal, vaginal or ultrasound assessment Non‐pharmacologocal use following administration of intervention or placebo Pharmacological or regional analgesia used following administration of intervention or placebo The proportion of women experiencing an at least 30% reduction in pre and post administration VAS scores The proportion of women experiencing an at least 50% reduction in pre and post administration VAS scores To determine the cost of SWI for back pain in labour compared with standard care. To determine the effect of SWI for back pain in labour on mode of birth To determine whether SWI for back pain in labour impacts on other maternal and infant outcomes in the short term Use of pharmacological analgesia prior to administration of intervention or placebo VAS of back pain following administration of intervention or placebo VAS of back pain prior to administration of intervention or placebo effect of SWI for back pain in labour on use of other pain relief methods INCLUSION CRITERIA: Term pregnancy (between 37 and 42 weeks gestation) Singleton pregnancy Cephalic presentation Back pain assessed by VAS as =7 when women request analgesia for backpain Able to give informed consent