Ueyama 1999.

Study characteristics
Methods	RCT
Participants	36 women Inclusion criteria: healthy full‐term parturients scheduled for elective caesarean during spinal anaesthesia Exclusion criteria: abruptio placenta, placenta praevia, multiple gestation, pre‐eclampsia, or women who were receiving ritodrine or other beta‐tocolytics
Interventions	Colloid preload versus crystalloid preload Group 1: 500 mL HES 6% Group 2: 1000 mL HES 6% Group 3: 1500 mL Ringer's lactate All solutions were infused over 30 min before injection of spinal anaesthesia. All women received a standardised spinal anaesthetic technique and dose.
Outcomes	Maternal: hypotension; blood volume; cardiac output
Notes	Hypotension defined as defined as decrease in SBP to less than 100 mmHg and less than 80% of baseline value
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Randomisation by random envelope method
Allocation concealment (selection bias)	High risk	No allocation concealment. Infusion bottle shape different between study groups
Blinding of participants and personnel (performance bias) All outcomes	Unclear risk	Not reported
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Unclear risk	Losses to follow‐up: not stated
Selective reporting (reporting bias)	Unclear risk	Not apparent, but not well reported
Other bias	Unclear risk	Not apparent, but not well reported