Farid 2016.

Study characteristics
Methods	RCT
Participants	74 women Inclusion criteria: healthy patients; elective CS Exclusion criteria: patients who experienced complications during the surgery Setting: Pakistan
Interventions	Crystalloid preload versus crystalloid coload Group 1 (P): received crystalloid preload 15 mL/kg Hartmann's solution 20 min prior to spinal anaesthesia Group 2 (C): received crystalloid coload 15 mL/kg Hartmann's solution at time of administration of spinal anaesthesia All women received standardised monitoring, standardised cannulation, standardised spinal anaesthetic technique and dose Hypotension was treated with vasopressor (phenylephrine or ephedrine)
Outcomes	Maternal: incidence of hypotension
Notes	Hypotension was defined as reduction in MAP by > 20% from baseline
Risk of bias
Bias	Authors' judgement	Support for judgement
Random sequence generation (selection bias)	Unclear risk	"Randomly assigned by trainee anaesthesia or anaesthetist in charge of case"
Allocation concealment (selection bias)	Unclear risk	Not reported
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	"Patients going into complications during surgery were excluded" – unspecified how many patients (if any) this involved. No further details provided
Selective reporting (reporting bias)	Low risk	Not evident
Other bias	Low risk	Not evident