The nurse put one in my daughter's mouth when she was a few hours old while they were taking her blood. She stuck to that thing like a tree frog to a sliding glass door, so I didn't have your problem. But there were some brands that seemed to fit better than others, so that's a good suggestion. However, after a few months, she would refuse any but her favorite brand, so when you find one that you both like, get a lot of extras. They have a habit of disappearing when you need them most.