Oh 2014.

Study characteristics
Methods	RCT
Participants	60 women Inclusion criteria: ASA I, elective CS under spinal anaesthesia Exclusion criteria: gestational age < 37 weeks, multiple gestation, fetal distress, pre‐eclampsia, cardiovascular disease, diabetes Setting: South Korea
Interventions	Comparison of crystalloid preload versus coload Group 1: rapid infusion of 15 mL/kg Hartmann's preloading Group 2: rapid infusion of 15 mL/kg Hartmann's just after intrathecal injection All women had same monitoring, IV access, spinal anaesthetic technique and dose. Hypotension treated with 5 mg IV ephedrine.
Outcomes	Maternal: incidence of hypotension, nausea and vomiting Neonatal: Apgar scores at 1 min and 5 min, umbilical cord gases
Notes	Hypotension defined as a decrease of SBP > 20% from baseline
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Low risk	Computer‐generated random allocation (block randomisation, block size 4)
Allocation concealment (selection bias)	Unclear risk	Not reported
Blinding of participants and personnel (performance bias) All outcomes	Low risk	Not blinded, but unlikely to have affected incidence of hypotension
Blinding of outcome assessment (detection bias) All outcomes	Low risk	Not blinded, but unlikely to have affected incidence of hypotension
Incomplete outcome data (attrition bias) All outcomes	Low risk	Group 1: 1 woman excluded due to surgical delay by other operation Group 2: 1 woman excluded due to inadequate spinal anaesthesia
Selective reporting (reporting bias)	Low risk	Not apparent
Other bias	Low risk	Not apparent