Kuusela 1998.

Methods	Randomisation stated but only described as 'by lots'. Methodological qualities: selection bias: no information; performance bias: high risk of bias could have been introduced because researcher could not be blind to group allocation after randomisation; exclusion bias: low risk of bias as no dropouts reported; bias conclusion: moderate bias. 1 or more criteria partially met. May raise some doubt about the results.
Participants	33 women, 18 water, 15 control In labour (cervix 4 cm dilated) Low risk ‐ term, 1 fetus, no complications in current or any previous pregnancy/birth
Interventions	Immersion in water during first stage of labour Intervention was use of bath for max of 60 minutes. Bath was thermally insulted, oval, size 150 cm by 110 cm, by 70 cm deep. Volume was 730 litres. Water temperature 37 degree Celsius No pharmacological analgesia available to either control or intervention group during study hour. After use of bath labour care as normal and could access 'usual' pain relief methods, positions. No mention of 1‐to‐1 care or not.
Outcomes	Duration of first and second stage of labour Pain relief used, pain score before and after study period (1 hour), own assessment in postnatal questionnaire on day 2 postpartum Blood loss, perineal trauma, Apgars Maternal pulse, temperature, blood pressure
Notes	Undertaken in Finland ‐ 1 hospital Dates of trial: April 1997 ‐ March 1998 Funding: not reported Declaration of interest: not reported
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Randomised 'by lots' in translation so very unclear what this means
Allocation concealment (selection bias)	Unclear risk	Described as randomised but translation does not indicate how concealed
Blinding of participants and personnel (performance bias) All outcomes	High risk	High risk of bias could have been introduced because women, carers and researcher could not be blind to group allocation after randomisation due to the nature of the intervention
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	No information provided
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Not reported
Selective reporting (reporting bias)	Unclear risk	Unable to assess this from translation
Other bias	Unclear risk	Full translation not available, just extracts as requested on Cochrane Pregnancy and Childbirth Group translation sheet