Parent's Child Prefab Loses Rotation

Quick question, I have made a prefab that has a plane as the Mesh. I also rotated it along the x axis -90 to face the camera. When I drag it to the stage it appears right (facing the camera).

But in my game I add these sprites at run time to a parent object and the mesh seems to reset to the old rotation of facing up.

Does the parent object need to be rotated at creation time? I'm guessing it does but wasn't sure how to do it properly with C#?

Thanks

Just worked it out. Turns out that it does set the rotation to that of the parent object well I think it does.

I corrected it by calling this when the object is created before it is added to the parent object

tile.transform.Rotate(new Vector3(-90,0,0));