Babies don't need to be burped when they can sit up on their own. Before that, the air bubbles are unable to rise out and get trapped in their bodies, causing them to feel uncomfortable if not burped. This is also why babies burp easily when held in an upright/seated position. http://sg.theasianparent.com/burping-your-baby/
I stopped burping my daughter at 5 months. Once they can sit up on their own, you don't have to worry about burping them.
Hi, i burped my babies till they are about 4 to 6 months old.
thanks