I had this happen, once they been sterized and washed few times it stops, but somebody from here rang tommee tippee to ask and they advised it's to do with the anti colic valve that sits in milk on the inside of teat as when new sometimes bit stiff so when the baby sucks the pressure builds up causing teat to go inwards. So they say to pinch it few times to open and close it to soften it then wash/sterilize as normal. hth

has any1 had the same prob as me? the 1st lot of tommee tippee teats i used came with the bottles bt wen i bort new 1z my DD keeps suckin them in at 1st i 4t they may b faulty so i bort mre itz a nightmare wen it comes 2 feed time i dno y it keeps hapenin can any1 help ?

lea x