"I have got too much on my plate," Aiken told the magazine, explaining why he was not involved in a relationship. "I'd rather focus on one thing and do that when I can devote time to it, and right now, I just don't have any desire."
After his son's birth, though, Aiken told Sawyer it was "an obvious time to just, you know, let the guard down and say, 'I have a responsibility for someone other than myself now.'"
Aiken told People magazine he expected some of his fans to be overwhelmed by the news. But after an outpouring of support from fans, Aiken wrote on his Web site: "Suffice it to say, for the first time in recent memory, I am speechless. I'm so proud to know and love all of you."
"It's taken a while for me to have faith in society to accept the fact that people are more accepting and more open-minded and more loving and caring and less interested in your personal life than I initially thought," he told "Good Morning America."
Aiken returned Tuesday to the Broadway musical "Spamalot," but he said he's most excited about his role as a new dad.
He's had talks with his mother, Faye Parker, about parenting and big dreams for Parker.
"And I've had to remind myself, you can't dream too specifically because everybody's the same way. ... But she [Faye] has done marvelously. It's great just to be able to be patient and expect things are going to take time," he said.
"Things don't change overnight."