In SharePoint 2010, I used this third party Managed Metadata Exporter from codeplex but it does not support SharePoint 2013. We had a requirement to export the terms for management review during a meeting. I found a powershell script to export on technet and although it is a pretty messy export, it does the job! Hope it helps.
https://gallery.technet.microsoft.com/office/PowerShell-for-SharePoint-a838b5d0