Dahlgren 2005.

Study characteristics
Methods	RCT
Participants	110 women Inclusion criteria: healthy women with normal term singleton pregnancies presenting for elective CS Setting: Sweden
Interventions	Crystalloid versus colloid preload Group 1: acetated Ringer's solution, 1000 mL, preceded by 20 mL 15% saline 0.9% IV Group 2: dextran 60 3%, 1000 mL, preceded by 20 mL dextran 1 IV All women received a standardised spinal anaesthetic technique and dose. Hypotension was managed by a standardised regimen of ephedrine dosing.
Outcomes	Maternal: hypotension; clinically significant hypotension; severe hypotension ephedrine consumption; blood loss Neonatal: umbilical artery < pH 7.2; pCO2; base deficit
Notes	Hypotension defined as SAP dropping below 100 mmHg; clinically significant hypotension as drop in SAP > 20% below baseline and severe hypotension defined as SAP < 80 mmHg
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	Not reported
Allocation concealment (selection bias)	Unclear risk	"Sealed envelope"
Blinding of participants and personnel (performance bias) All outcomes	Low risk	"Double‐blinded" – solution prepared and administered by an anaesthetic nurse not otherwise involved in the care of the woman (including the initial injection)
Blinding of outcome assessment (detection bias) All outcomes	Unclear risk	Not reported
Incomplete outcome data (attrition bias) All outcomes	Low risk	Losses: 1/110 – 1 woman from crystalloid group excluded due to protocol violation; 1 woman allocated to crystalloid subsequently found to have received colloid.
Selective reporting (reporting bias)	High risk	Not all outcomes listed in the paper were reported
Other bias	Low risk	Some baseline differences, e.g. 32% nulliparous in the crystalloid group compared with 21% in the colloid group