I suppose in theory, this sort of slogan on a baby shirt is cute:
I mean, all my kids are well loved and cherished and all that. It's a sweet sentiment. However, let's think about the phrase "made with love" in regards to a human being. How do we make babies, kids? Yes, that's right: SEX.
So, as sweet and cutesy as a shirt like the above can be, in essence, I would be plastering information about my sex life all over my young, innocent child. When you look at it that way, it's actually kind of gross and creepy. "My parents had hot, passionate love in order to make little ol' me!"
Um, let's keep that sort of thing off of t-shirts, 'kay?