Date	Event	Description
9 August 2016	New search has been performed	Search updated– last published included 75 trials, now includes 126 trials. Note: we excluded 13 trials included in last update because they assessed combined spinal‐epidurals rather than spinal anaesthesia, and we excluded one study because it failed to report our primary outcome. Author list and order updated for this version of the review. We excluded quasi‐randomised trials in this version. We also excluded trials where women received epidural anaesthesia or combined spinal‐epidural anaesthesia. We have incorporated seven 'Summary of findings' tables into this update.
9 August 2016	New citation required and conclusions have changed	Conclusions changed with this update. Ondansetron may be a useful intervention, and fluid coloading is more effective than preloading.
30 June 2010	Amended	Search updated.Eighty‐five trial reports added to Studies awaiting classification.
18 February 2008	Amended	Converted to new review format.
6 June 2006	New search has been performed	The 2006 update now contains 75 included studies. Forty new studies have been added and 10 previously excluded studies have now been included. These studies were previously excluded as there was some variation between women in the dose of anaesthetic. An additional 38 studies were excluded and appear in the Characteristics of excluded studies table with reasons for their exclusion. The new studies reinforce the previous conclusions and also show that phenylephrine is also likely to be effective in preventing hypotension.