Fatherhood is the state of being a father. Everything that comes with it, not the moment it began.
The word covers the role rather than the biology, and writing about fatherhood is usually writing about what it changes in a man. It sits alongside motherhood and parenthood, and the three have very different histories in English, since motherhood has been written about for centuries and fatherhood mostly for the last fifty years. There is a fixed phrase in the joys of fatherhood, which is used sincerely about half the time.
1nounfatherhoodThe state or experience of being a father.
“Fatherhood had changed him completely.”
Middle English
faderhode
English, today
fatherhood
From Middle English faderhode, fadirhode, fadirhede, equivalent to father + -hood.
Etymology from Wiktionary, CC BY-SA