Originally, Meyer wrote a book titled Forever Dawn, which was a direct sequel to Twilight. While the basic storyline remained the same, Forever Dawn was narrated completely from Bella's point of view, the werewolves and Jacob were "only sketchily developed", Victoria and Laurent were both alive, and there was an epilogue. Meyer went on to say that she "may post some extras someday if I ever have time to go back through the Forever Dawn manuscript—it's just as long as Breaking Dawn."
The part that took Meyer the longest time to write of Breaking Dawn was the half-chapter describing the 3 months after Bella's transformation into a vampire because "the amount of time per word put into that section was probably ten times what it was in any other part of the book" and Meyer liked to write minute by minute, but didn't think it would be exciting.
Meyer decided to include the pregnancy in her story while she was researching vampires, early in 2003, and came across the legend of the incubus, a demon who could father children. Bella's insistence to not let her child die was inspired by Meyer's reaction when asked if she would let one of her children die so she could live, which was to deliver the child no matter what the consequences were. Meyer said in an interview with Shannon Hale, published in The Twilight Saga: The Official Illustrated Guide, that the birth scene published is a little less grotesque than the one she wrote before editing due to her editor, agent and publisher's requests to "tone down the violence a little". She stated that Bella's pregnancy and childbirth, for her, were "a way to kind of explore that concept of what childbirth used to be" in the past and acknowledged that they were "taking Bella in a new direction that wasn't [as] relatable for a lot of people." Concerning the subject of the relatability of Bella, Meyer admitted that she lost some of her relatability to the character when she became a vampire and said, "every point up until that point in the story [the transformation] I would say I could step into this story right here and I could do everything she could do which made it really fun." Meyer wanted to experience Bella's vampiric experiences and "enjoyed very much" writing about them and wanted to end the book from her perspective, but still thought it was "a little bit harder" as she couldn't step in into the story anymore.
In regard to Renesmee's unique name, Meyer wrote that she "couldn't call her Jennifer or Ashley. What do you name the most unique baby in the world? I looked through a lot of baby name websites. Eventually I realized that there was no human name that was going to work for me, so I surrendered to necessity and made up my own."
Meyer states in regard to ending the series:
The Twilight Saga is really Bella's story, and this was the natural place for her story to wind up. She overcame the major obstacles in her path and fought her way to the place she wanted to be. I suppose I could try to prolong her story unnaturally, but it wouldn't be interesting enough to keep me writing. Stories need conflict, and the conflicts that are Bella-centric are resolved.
The plays The Merchant of Venice and A Midsummer Night's Dream by William Shakespeare both influenced Breaking Dawn. Meyer decided that Alice would write her instruction to Bella on a page from The Merchant of Venice to give a clue that the final confrontation at the end of the book would be a mental one—not a physical battle—like the one at the end of the play. It also hints that the novel would have a happy ending for the couples, as in The Merchant of Venice. Originally it was the novel Jane Eyre by Charlotte Brontë that Alice tore a page from, but Jane Eyre had nothing to do with the story, so Meyer changed it.
The idea of imprinting, which existed in Forever Dawn, was inspired by A Midsummer Night's Dream. Meyer described it as "the magic of setting things right—which doesn't happen in the real world, which is absolutely fantasy", and decided to introduce it earlier–in Eclipse–so she wouldn't have to explain it later.
Meyer described the cover as "extremely meaningful" and said that she was "really happy with how it turned out". The cover is a metaphor for Bella's progression throughout the entire series; she began as the physically weakest player on the board, the pawn, but at the end she becomes the strongest, the queen. The chessboard also hints at the conclusion of the novel "where the battle with the Volturi is one of wits and strategy, not physical violence."
The title, Breaking Dawn, is a reference to the beginning of Bella's life as a newborn vampire. Originally, Meyer wanted to title the book Forever Dawn, but she thought the name was very "cheesy". Wanting to add a "sense of disaster" to the title to match the novel's mood, she called it Breaking Dawn. Another reason for giving the book this particular title is that it matches the book's plot, which centers around "a new awakening and a new day and there's also a lot of problems inherent in it".