Anyone knows the rationale behind changing bottles after 6 months? Currently using Pigeon wide neck bottle and didn't change since Day 1, feeding majority ebm and sometimes fm. LO is 13 months (gasps!) is there any health concern?

Well i guess its for hygiene purposes. After all the bottles are plastic and the teats are silicone. It will have a wear and tear theory as well plastic is not like glass. A minimal amount of residue remains. I change mine every 3 months.