I am aware of a connection between Irving's life and The World According to Garp. Irving attended Philips Exeter Academy, and while he was there, he wrestled. I do not know if you have read Garp, which is my favorite of all his books, but the protagonist wrestles, too, and ends up marrying the coach's daughter.
There is also a connection in Irving's life with The Cider House Rules, which a strongly pro-choice novel. The father of Irving's stepfather, who was for all practical purposes his grandfather, since his stepfather had married Irving's mother when Irving was about two years old, was a gynecologist and obstetrician, and strongly pro-choice. This apparently was a strong influence on Irving.