Table 2 Labour length and retrospectively reported pain and satisfaction among nulliparous women with dystocia allocated to labour in a birth pool or standard augmentation (amniotomy and intravenous oxytocin). Values are numbers (percentages) of women unless otherwise indicated

Outcomes Labour in water (n=49) Augmentation (n=50) Mean differences (95% CI) P value Mean (SD, range) length of first stage of labour (hours) 10.47 (3.69, 3.75-19.32) 10.26 (3.75, 4.25-21.37) 0.22 (-1.27 to 1.70) 0.677 Pain score (visual analogue scale)*: Mean (SD, range) pain score 30 minutes after start of management (0-100 mm) 49 (22, 8-96) 64 (30, 0-100) -16 (-27 to -5) 0.003 Mean (SD, range) change in score after 30 minutes of management (-50 to 50 mm) -26 (16, -50-28) 12 (32, -50-50) -38 (-49 to 28) <0.001 Maternal satisfaction (n=47)* (n=48)* Relative risk of satisfaction (95% CI) With freedom of movement: Satisfied 43 (91) 30 (63) 1.46 (1.18 to 1.91) 0.001 Satisfied and dissatisfied 4 (9) 15 (31) Dissatisfied 0 0 Not sure 0 3 (6) With privacy: Satisfied 45 (96) 39 (81) 1.18 (1.02 to 1.42) 0.029 Satisfied and dissatisfied 2 (4) 9 (19) Dissatisfied 0 0 Not sure 0 0 With overall management: Satisfied 44 (94) 42 (88) 1.07 (0.93 to 1.26) 0.486 Satisfied and dissatisfied 2 (4) 6 (13) Dissatisfied 1 (2) 0 Not sure 0 0

Mann-Whitney test. Pearson ² test. Exact ² and confidence interval.

^* Postnatal interviews were conducted for 48 women allocated to augmentation and 47 women allocated to labour in water. A further two women in each group declined to answer the pain questions.