Statistical analysis was performed using OpenMetaAnalyst software.



OpenMetaAnalyst
PubMed, Embase, Medline and Google scholar were searched systematically until December 2017 for articles reporting epidural failure and/or difficulties in epidural placement in obese pregnant women and non-obese pregnant women. 
PubMed
PubMed, Embase, Medline and Google scholar were searched systematically until December 2017 for articles reporting epidural failure and/or difficulties in epidural placement in obese pregnant women and non-obese pregnant women. 
Embase
PubMed, Embase, Medline and Google scholar were searched systematically until December 2017 for articles reporting epidural failure and/or difficulties in epidural placement in obese pregnant women and non-obese pregnant women. 
Medline
PubMed, Embase, Medline and Google scholar were searched systematically until December 2017 for articles reporting epidural failure and/or difficulties in epidural placement in obese pregnant women and non-obese pregnant women. 
Google scholar