The actor and his 102 Dalmatians co-star Alice Evans recently confirmed that they were expecting their first child together in September.
Speaking to People, he said: "It's been one long summer because my wife is pregnant... I have basically been the best husband in the world, or trying to be!
"You go from being lover to husband, lackey, taxi driver. You just have to have so many caps on. Listen, it's a blessing that I am here, at home not working, being able to be there for her."
Gruffudd, who tied the knot with Evans in Mexico in 2007, added that the couple already knew the sex of the baby and had considered a "handful" of baby names.