When Victoria Rowell became pregnant during hiatus, her pregnancy was explained by having her get married to a serviceman who was never seen on the show.
The character of Doctor Mark Sloan was first seen in an episode of "Jake and the Fatman" (1987).
When Scott Baio left the show, his absence was explained by having his character, Jack Stewart, quit his job at Community General to start his own practice in Colorado.
In the 1999 episode "Gangland", it is revealed that Amanda was a foster child. Victoria Rowell, who played the character, was a foster child in real life.