What goes into editing? Sometimes a lot, sometimes a little. Editing is a way for the photographer to polish an image. I shoot RAW image files, which means I need to go through the files and edit them for colour and sharpness.
Newborns are specifically tricky because they are often jaundiced (yellow skin) or have newborn skin issues (flaky skin, rash, milia, baby acne) etc. I try to keep my skin editing to a bare minimum, so as not to take away from the reality of the moment and image.