Ahh Interesting, I have never heard the term top feed before!
I am guessing you mean giving formula? I can't really speak for all the US on this one but just talking with our other friends with babies, most women want to breastfeed 100% but will do some formula to supplement as well; it really just depends on their situation! 😊
Top feed is the term frequently used here. Hehe.
Thanks for providing the details.