The couple welcomed daughter Billie Beatrice Dane on March 3 at the Cedars-Sinai Medical Center in Los Angeles.
The first public pictures of the child appear in the new issue of US Weekly.
Speaking to the magazine, Dane - who plays Dr Mark Sloan in the ABC medical drama - said: "She's beautiful. When she came out, she was really alert and her eyes were open. The doctor gave her to her mum, and I was so... you know, I was obviously very emotional."
He continued to say that being a father has been a "life changing" experience, saying: "Childbirth is a miracle and we've created this life."
Gayheart added: "[Giving birth] was an overwhelming moment - probably the greatest moment in my life thus far. We felt so blessed. The moment we've been waiting for finally came."
