When exporting from a Summary field in Export using Total Gift Amount there are several options available.

**If you want the original amount of the Pledge go to the Gift Types tab and include Pledge and do not select the option to Use Gift Balance instead of Gift Amount
No Gift Balance
**If you want the current balance of the Pledge, the Use gift balance instead of gift amount should be marked
Use Gift Balance
**If you want the original Pledge amount, but do not want to include Pledges that have been written off, you will need to include a Gift Query as a Filter in the Summary field
Gift query with no write off
Include that GIFT query in the export on the Filter tab

Filter using Gift Query