Depending on condition. I will recommend ppsu bottle which don't need to change so often. Teats wise I will change once it turn yellowish.
Teat I keep changing once baby gets frustrated when drinking.. the hole too small.. need to change always
Bottle nipple more regular...every 2-3 weeks for me but the bottle every 3 months
Depending on the condition of the teat, I change the it around 3 mnths or so.
3 months for nipples and 6 months for bottles
Not as often as recommended 🙊