WinForms : "Not Responding" When Adding Rows To Datagridview?

I've got a method that makes a request to a service that queries an SQL database, and then adds the result of the query in a datagridview row. I call that method in a "for each" loop.

It looks like this:

For each item in BigListContainingHundredofItems
Dim rowdata As String = GetRowResult(item, SomeDatabaseConnectionString)
Datagridview1.Rows.Add(rowdata)
Next

Basically hundreds of inputs are sent to the "for each" loop, and the way I've written it now it becomes "Not Responding" until all the rows have been added to the form (I can see the scrollbar handle size shrinking, which means rows are getting added).But I'd like to know how to keep everything responsive, and I think multi-threading or background worker thread might be the solution. I just wanted to get some input/feedback from the community.