Last-Minute Baby-Naming

In Real Life, parents tend to use the entire nine months between conception and birth to think up names. They buy baby books, make compromises, and if they don't know the sex of the baby then they choose one for each gender, just to be prepared.

But not in media. In media, parents go the entire nine months without even thinking or talking about it. When it finally comes to the birth, one of the parents says "what should we call him/her?" and then they patch together a name on the spot while holding the child, with minimal, if any, need for discussion on the matter between the two parents. A Line-of-Sight Name or Dead Guy, Junior names are common. Naming it after the mother or father's deceased parent is a particularly common option.

While it does sometimes happen in Real Life that parents wait to the last minute to name their child, usually because they want to be inspired upon finally seeing the child, or one of them is fixed on a name that the other can't stand, it seems highly unlikely that it is as common as the trope's frequency implies.

Compare Line-of-Sight Name, Meaningful Name.

Anime and Manga

 * A chapter in Oishinbo revolves around the Official Couple deciding on names for their twins after the birth. The male lead has to be extra convincing to explain the Meaningful Name he's giving his daughter.
 * In Dragon Ball, Goku and Chi Chi had a hard time thinking of a name for their firstborn son after he was born. Until Chi Chi's father realized that the baby responded the best to Goku's grandpa Gohan's name and the rest was history.

Comics

 * In Baby Blues, Wanda and Daryll's third child is only named Wren because a bird flew into the window while Wanda was recovering in the hospital.

Film -- Animated

 * In Ice Age 3, Manny and Ellie have apparently not decided on what to name their child. After the baby mammoth's birth, Manny suggests they name her Ellie, but Ellie decides on the name "Peaches", which had been their code word for Ellie to tell Manny she was going into labor.

Film -- Live Action

 * This happens at the beginning of Star Trek, when Kirk's parents are naming him. He's named for his maternal grandfather, and his middle name is his paternal grandfather's.
 * In the third Star Wars prequel movie, Padme doesn't name her twins until they are born, and she's dying.

Literature

 * The Parasol Protectorate: Alexia and Conall Maccon don't talk about baby names at all for the entire time Alexia is pregnant, and name their daughter on the spot after she's born. Until that point Alexia just called her the 'infant-inconvenience'.
 * Justified in A Song of Ice and Fire. With the Grim Up North conditions behind the wall, the mortality of children is so high that naming one that hasn't yet grown enough to walk is considered Tempting Fate.
 * In I Should Have Seen It Coming When the Rabbit Died by Teresa Bloomingdale, Teresa gives birth to her 3rd child. Her husband comes into her hospital room saying "That baby isn't Jimmy". Her initial response is "Well, it certainly isn't Mary!" (They'd picked the name James for a boy, Mary for a girl. They did use those names for later arrivals.) They finally decide the baby is Michael.
 * Happens a lot in the Book of Genesis. Probably the most memorable examples would be Jacob's sons, but other examples abound.

Live Action TV

 * Community: After Chang helped Shirley through her child delivery, she decides to name her baby after him. Then she realizes how unfortunate "Ben Bennett" sounds, but sticks with it anyways.
 * Friends:
 * Ross names his son Ben after a series of mishaps which befall Ross and his ex-wife's partner at the hospital while she's busy having the baby; at one point there is a janitor's coverall involved which has the name "Ben" on it. Prior to that they were feuding over what to name him.
 * Also from Friends: Soon after Rachel gives birth, she can't decide what to name her daughter. When Monica tells her that she plans to name her own future daughter Emma, Rachel likes the name so much that Monica lets her have it.
 * Clare on Lost doesn't name her baby "Aaron" until after he's born, resulting in a "whodat" reaction from Charlie after she uses the name for the first time.
 * Mad About You: Paul and Jamie name the baby Mabel, after a remark by Jaime's mom. "Mothers always bring extra love." It's the topper to a bunch of parenting advice she gives them, all of which have Fun with Acronyms as mnemonic devices except that one (until Jamie notices it).
 * In The Secret Life of the American Teenager, this happens three times.
 * Amy gives birth to her son at the end of the first season and, having not thought about any names, her sister offers up the name John. (Possibly justified in that Amy hadn't been certain for most of the pregnancy that she wouldn't give the baby up for adoption.)
 * In the second season, Amy's brother Robbie is born, and is named on the spot after her grandfather.
 * At the end of the third season, . They hadn't discussed names at all during the pregnancy, but it is revealed the following season that they named her Mercy.
 * Murphy Brown went even further, having gone through multiple names for her unborn child during her pregnancy and kept going even after he was born. Eventually she names him "Avery" after her recently deceased mother.
 * On Roseanne, Jackie bemoans the fact that she's in labor and hasn't even picked out a name yet. Her mother Bev cheerfully suggests that she just pick anything and get it changed later if she wants. She then reveals that they actually did this with Jackie, who was originally Marjorie. Actually, she admits that they may not have gotten all the paperwork done for that, and suddenly Jackie is freaked out that she doesn't know her own name either.
 * Justified on Angel--Darla wanted to just get rid of her pregnancy, but can't, Angel just found out the child existed and nobody was sure if it would even be a baby or some sort of demonic monster, since vampires aren't supposed to be fertile in the first place. Then half of L.A.'s supernatural community was hunting them for some reason, and a full episode after the baby was born Angel just sort of announces that his name is Connor when the doctor asked.
 * Happens in Scrubs with the birth of JD's son, of the Dead Guy, Junior variety. To be fair, JD didn't have a lot of time to plan as he was completely unaware that he going to be a father until a few weeks beforehand.
 * Danny and Lindsay on CSI: NY don't agree on their baby's name even after she's born. Danny says 'Lucy' and Lindsay says 'Lydia'. (it's said in the next season to be Lucy).
 * Toby on the The West Wing names his daughter 'Molly' after a secret service agent who died on the same day his daughter was born.
 * Susan and Mike on Desperate Housewives discuss what to name their son before deciding to name him Connor...until Mike's grandfather dies and he wants to name their son in his memory. The problem? His name was Maynard. Despite Susan's distress and discomfort over the choice, and attempts to change it, she has a change of heart after Mike explains how much his grandfather meant to him. Thankfully, the kid is referred to as "MJ" in following seasons.
 * The only time baby names are mentioned for  in Farscape is during a brief joke in The Peacekeeper Wars. They end up pulling a Dead Guy, Junior at the end of the movie and naming him

Video Games

 * Wakka and Lulu's son in Final Fantasy X-2 doesn't get named unless you complete a sidequest, and if you fail or skip the quest, then Rikku jokes that the kid might go nameless until he hits puberty.

Web Comics

 * Played with in Schlock Mercenary. Edward Bunnigus explains the circumstances of her naming; Her parents were too stupid to be allowed to breed, so they had her genetically created, and when she was born, they chose to name her Edward, after the ED tag on her (it stood for "exotic dancer" because that's the model of baby they wanted, but they thought Ed was the name the hospital gave her).

Western Animation
"Mr. McCormick: God, this must be the 50th time this has happened. Mrs. McCormick: Fifty-second."
 * In one episode of South Park, Kenny's mom is pregnant. After his Once an Episode death, the baby is born and the parents decide to name the new baby Kenny.

"Didi: He doesn't look like a Trixie."
 * Avatar: The Last Airbender: Ying and Than, the expecting couple whom Aang helps in The Serpent's Pass, don't name their baby until she is born. The child, Hope, becomes the only character in the show with a non-Asian name.
 * The Flintstones also named Pebbles only as soon as she was born.
 * Justified in the first Rugrats movie--Stu and Didi apparently thought that Dil would be a girl, and had to revise their plan to name "her" after Stu's mother.

Real Life

 * Queen Victoria's parents wanted to name her Georgina in honor of her uncle, Prince George of Wales, but he vetoed it at the christening and suggested they name her after her mother instead.
 * In places that have or had a high infant mortality rate, it was not uncommon for the culture to adopt a custom of not naming the baby until it was a month old or older, just in case it died.
 * It's also not uncommon for parents to name a baby as an afterthought if the baby isn't the gender the parent(s) were hoping for and/or the baby turned out to be two (or more) babies, and the parent(s) weren't prepared with multiple names.