the size is important, but the ice will actually melt before it can do any harm if it does get stuck in the throat if it is small enough. Charlotte has been having icecubes since she was 6 months old and we have NEVER had an issue at all. She knows how to suck on them and will spit them out and suck them up again and agian until they ae small enough for her to chew on. She loves them!!
Like I said though, the size is definately important.