"In our pain and our hurt, a blessing came out of it … a son that was born healthy," the Miami Heat star, 31, said at a press conference Monday. "So, I'm moving on."
Wade acknowledged that he and Union, 41, have been working through the issue together, but added that he was proud to have a third son.
"Me and my lady and my family have continued to move forward, and I think that's evident with the ring and the proposal that I gave her," he said. "This is something, obviously, private for my family that we will continue to deal with as a family, but we have a blessing to the bloodline, to the Wade bloodline."
The three-time NBA champion has two sons – Zaire, 11, and Zion, 6 – from his marriage to Siohvaughn Funches and also has custody of a nephew.
Of the new arrival, he said: "I've gotten a chance to see him. You know me. I'm involved in my kids' lives."