Study	Reason for exclusion
Bastide 1990	Unpublished data from 1990 available only. Inadequate data for assessment at this time. We contacted the author for further information, but nothing was provided
Benfield 2001	Only 18 women, 9 in each group. Randomsied by drawing slips of paper from a total of 52 paper slips in a bag which is inadequate allocation concealment. Women were in a limited depth of water; were asked to adopt a semi recumbent positions on a partially inflated air raft with attached head pillow (authors description) for 1 hour, and had cannulation to facilitate repeat blood samples. All of which limits mobility and is not consistent with water immersion in normal labour
Calvert 2000	Results of this pilot study (22 women) are not given in a format that can be used in the review. The aim was to compare the effect of the essential oil of ginger compared to essential oil of lemon grass on the progress of labour. The pilot study showed no differences on frequency of contractions, cervical dilatation or duration of first stage of labour between the 2 groups
Cluett 2001	Feasibility study: only 4 women in each of the 3 trial arms. Women had all been diagnosed as having dystocia in the first stage of labour (less than 1 cm/hr progress after established labour)
Cluett 2004	Women had all been diagnosed as having dystocia in the first stage of labour (less than 1 cm/hr progress after established labour) and the comparison group was women receiving augmentation of labour
Labrecque 1999	The method does not meet the inclusion criteria for this review. It is impossible to disentangle the effects of immersion in water. The aim of the trial was to compare 3 non-pharmacological approaches to relieve back pain. A total of 34 women were randomly allocated to receive 1 of 3 treatments: (1) intracutaneous sterile water injections, (2) transcutaneous electrical nerve stimulation and (3) standard care that included back massage, whirlpool bath and liberal mobilisation. The sample size is small and results should be interpreted within the setting only. Women in the ISW group experienced a decrease in the intensity and unpleasantness of their backache, but they would not like to use this method in a future labour

ISW: intracutaneous sterile water injection