Pending links with a Word Press powered blog can grow really quickly and most is spam. Word Press allows you to remove such comments but only 20 at a time. What if you have thousands?
If you login to your hosting panel, access phpadmin, access your database, click SQL, input the below command click ok, all pending comments will be removed.
If unsure, seek help from a professional
DELETE FROM wp_comments WHERE comment_approved = '0'