How do I know when to change to the next size teat?

We recommend that you get the cues to change size from your baby rather than the teat packet. Age recommendations for teats are very difficult because each baby develops at a different rate.
Ways you can tell that you should move up a size:
– your baby is fussing every time they feed – this could mean that they are getting frustrated with the flow of milk from the bottle as it’s not coming fast enough.
– the teat keeps collapsing when the baby is drinking, (and it’s not because the air flow valve is blocked). This can mean that the baby is sucking too hard for the size of the hole in the teat and a vacuum is being created, hence the teat collapses. The baby is trying to drink faster than the size of the teat will allow.