Written-In Infirmity

Occasionally a show's writers will have to work around a very real physical circumstance involving one of the actors -- ie, a temporary medical complaint.

A subtrope of Real Life Writes the Plot. See also Reality Subtext. If it's a pregnancy, expect either But I Can't Be Pregnant or Hide Your Pregnancy. The Logical Extreme is The Character Died with Him, when the show's writers have to take into account an actor's death.

Film

 * The famous scene in Raiders of the Lost Ark where Indy summarily shoots a sword-waving assailant was apparently supposed to be a show-offy sword duel - but Harrison Ford had the raging shits so they wrote the version we see in the film instead. Interesting as it became an in-joke in the films; in the sequel, he goes to do the same thing... only to find his gun's not there. Cue hilarity. In the third one he pulls it out to try to shoot a plane... but it's out of bullets. So his father comes up with a creative solution involving an umbrella and a flock of seagulls.
 * Of course, this is an example of Anachronism Stew, as the "sequel" Temple of Doom was actually a prequel to Raiders of the Lost Ark, yet Indy makes the "oh I've handled this situation before" grin. Possibly done because of the Rule of Funny or Rule of Cool.
 * Also, Harrison Ford has a scar on his chin from a car accident. For the third movie they added a scene in which young Indy uses a whip for the first time and accidentally slaps himself across the chin with it to explain Indy's scar.
 * In fact, multiple films with Harrison Ford have his character throw in an aside about that scar. Even Working Girl.
 * This trope was parodied in Stuck On You, where a conjoined twin wants to be an actor but his brother has stage fright. The film then shows executives trying to work around this, first by incorporating him into the environment, then by putting him in a Blue Screen suit.
 * In Real Life, there's a pair of women joined at the temple, one of whom is pursuing a career in country music. No clue how the possible stage performances are going to go.
 * While filming a chase scene in Se7en, Brad Pitt severed a tendon in his hand and had to wear a cast. A scene was added to the film showing that his character broke his arm while pursuing the killer.
 * In the film version of You Can't Take It With You, Lionel Barrymore's arthritis had worsened to the point that he performed his role on crutches, the character being said to have injured his foot. In later film roles, Barrymore performed from a wheelchair.
 * Featured prominently in Freaks, which would have had no point at all if it attempted to make the cast appear "normal."
 * In a videotaped performance of Cats made in 1998, John Mills plays Gus the Theatre Cat. Mills had been nearly completely blind since 1992. This was gotten around very effectively with a younger cat guiding Gus around the stage, the actors making it look quite natural that the younger cat was hovering over and guiding the much older cat, with Mills even moving his eyes and head to fit the action.
 * Happened when Halle Berry broke her arm while filming Gothika; an injury was duly written in to explain away her plaster cast.
 * Tim Meadows broke his wrist shortly before filming Mean Girls. His cast is explained as Carpal Tunnel Syndrome, which gets pretty weird since the film takes place over an entire school year.
 * Mark Hamill broke his nose in a car accident shortly after the first Star Wars film was released, and so he spends the first five minutes of The Empire Strikes Back with snow gear covering his face, and then a wampa smacks him. It ended up working out quite well for the character: the injuries had completely healed by Return of the Jedi, and the changes to Hamill's facial structure made him appear much more mature, just like Luke was supposed to be.
 * It was apparently more than just a broken nose- it was at the very least a badly fractured nose and cheek, and one story says that the tip of his nose had to be reconstructed using a piece of his ear. This supposedly explains the nearly morticians-grade makeup job he received on the set of "The Star Wars Holiday Special''.
 * Several of the actresses in A League of Their Own were injured filming the baseball scenes, with no attempt made to cover them up as it made them more realistic as having been playing for some time. In one case a shot was added to a montage to showcase one actress's gigantic bruise on her hip.
 * In the WWII-era film The Train, the main character Labiche, played by Burt Lancaster, is shot in the leg. This was added because Lancaster had injured his knee playing golf, but it serves to make the final scenes of the film even more tense and exciting.
 * This was done in Transformers: Revenge of the Fallen; since Shia LaBeouf injured his arm in a car accident during production, Sam Witwicky injured his arm after
 * Chico Marx was in a car crash that shattered his kneecap, during the filming of Horsefeathers. One scene, shot shortly after, has Harpo, trying to kidnap two football players and getting beat up, while Chico sits in a chair and directs him.
 * An in-universe one in State and Main, where the star of the film-within-a-film slices up his forehead in a car crash. It's worked in quite naturally as his character starts the film having returned from putting out a large fire.
 * The Three Stooges faced such a situation when they were about to film You Nazty Spy! when Larry Fine injured his foot just before shooting and had to walk with a noticeable limp. Fortunately, this was perfect for his role as a parody of Josef Goebbels, who himself walked with a limp due to a clubfoot.
 * In the shorts leading up to Curly's untimely stroke that forced him into retirement, efforts were made to write more scenes with just Moe and Larry so he could rest, and Stock Footage from past shorts were spliced in to fill up time.
 * After horrific skin problems from the prostheses he wore in The Santa Clause, Tim Allen had "desantification" added to the second movie so he could limit his time in the Santa makeup. However, the later addition of a robot Santa meant he had to be in costume even longer than the first movie.

Live Action TV

 * Pruitt Taylor Vince has pathologic nystagmus, and so do some of the characters he played, e.g. on The X-Files and House.
 * James Masters has a scar on his left eyebrow from a mugging. This was written into Buffy the Vampire Slayer canon when his character Spike gets cut in the same spot while fighting a Chinese Slayer during the Boxer Rebellion.
 * In the third season of 3rd Rock from the Sun, John Lithgow (Dick) broke his leg playing tennis or racketball or something. Dick (who never stands in the episode immediately after the accident) rides a wheelchair down the stairs breaking his leg. This is complicated because Dick had already sprained his ankle in season two. (Most plots revolve around the characters learning about some aspect of life on Earth, like say getting injured).
 * When actor Jerry Seinfeld had laryngitis, character Jerry Seinfeld made a comment about losing his voice after performing a very rowdy set.
 * In another episode, the character Elaine screams at a barking dog all night. The actress (Julia Louis-Dreyfus) injured her voice filming that scene, so her character was given the same injury.
 * When Matt LeBlanc had a sling on his arm, it was turned into a very effective joke on Friends about Joey having a bed-jumping mishap.
 * On 24, Carlos Bernard injured his ankle playing basketball, and hence, his character Tony Almeida hurt his own ankle and started using crutches. Because a season of 24 takes place over the course of a day, Tony was still using crutches long after Carlos Bernard's ankle had healed.
 * When Lucy Lawless was thrown from a horse during a stunt on the Tonight Show, it led to several episodes of Xena: Warrior Princess being written to have less action than a usual episode or Xena in someone else's body.
 * There was also the time in season 3 when Gabrielle broke her ankle trying to imitate Xena's somersaults. Renee O'Connor really did break her ankle during shooting. Then Gabrielle was poisoned by Persians.
 * When Anissa Jones, Buffy on the '60s Dom Com Family Affair broke her leg, the writers wrote it into the show.
 * When actor Jared Padalecki injured his wrist in a stunt on an episode of Supernatural, his character was tackled in the next episode, explaining the presence of a cast for the next four episodes.
 * Very naturally used in the third season of Babylon 5. While filming a fight scene for the episode "Severed Dreams," actor Jerry Doyle broke his wrist. His character, Michael Garibaldi, was originally supposed to end up with an injured leg (and in fact, due to the shooting schedule, does appear with a leg injury briefly), but his arm is in a sling for the following episode, "Ceremonies of Light and Dark," explained on-screen by Garibaldi breaking his wrist during the same fight.
 * Also in the show's second season episode "The Geometry of Shadows," where Claudia Christian's real-life broken foot was explained by having her character get caught in the middle of an alien melee. Contrary to myth, she didn't break it on set; her very real cry of pain during the scene in which her character is injured was caused by her landing awkwardly, but this didn't cause her real-life injury.
 * The only Power Ranger that has ever been killed off on the show is Kendrix Morgan, after actress Valerie Vernon collapsed on the set of Power Rangers Lost Galaxy and was diagnosed with leukemia. (It sounds insensitive, but the series takes place on a space station, and there are no Peace Conferences in the Lost Galaxy). Her character returns to life in the Grand Finale and, fortunately, she recovered. In time to film the Reunion Show, even.
 * When Michael Shanks had to sit out an episode of Stargate SG-1 after having an appendectomy, his character sits the episode out for the same reason. Also, instead of a scripted scene, Shanks got to ad-lib the discussion of his illness with Richard Dean Anderson. ("Can I see the scar?" "...No.")
 * When Stephen Colbert broke his wrist before an episode of The Colbert Report, the next few weeks were full of wrist jokes like Colbert starting WristStrong, which raises awareness for wrist injuries. Colbert's character also became addicted to painkillers, and started doing things like filling the empty bottle with water to make "pill juice," and crushing pills and putting the dust in his eyeballs. He even had his cast removed on air and sold it for charity. It raised $17,200.
 * The WristStrong campaign included selling red rubber bracelets, parodying Lance Armstrong's LiveStrong bracelets. As of January 2008, WristStrong raised $171,525 for the Yellow Ribbon Fund.
 * Dana Elcar's character in MacGyver became severely visually impaired from glaucoma when Elcar developed the condition.
 * During the filming of the tenth episode of the original Kamen Rider, actor Hiroshi Fujioka (who also portrayed Segata Sanshiro in the Japanese marketing campaign for the Sega Saturn) was thrown from his motorcycle after crashing into a telephone pole, breaking both of his legs. How do you fix up the plot when your main character has just crippled himself? Easy; Create another Kamen Rider, Kamen Rider-2!
 * This was because Fujioka did his own stunts up to and including wearing the Kamen Rider suit. After this however it was required for all tokusatsu program leads to have a separate suit actor for fight scenes to prevent a problem like from occurring again.
 * A particularly tragic example occurred in the last series of The West Wing: John Spencer, who played chief of staff Leo McGarry, had suffered from heart troubles. When the time came for him to resign from his position in show, his character had a heart attack. He later wound up being named as a vice presidential nominee in the show's final season, but during the course of filming the final season (during which his character's health and capacity to continue such a grueling campaign schedule was repeatedly questioned by the press), Spencer suffered a fatal heart attack. The first new episode after his death again prominently featured Leo, and included some very uncomfortable lines when viewed with the knowledge of what had happened - which even the most shut-in viewer had, as Martin Sheen recorded a touching tribute to Spencer at the start of the episode.
 * Another example from The West Wing comes from 2001 when Stockard Channing broke her ankle hiking. Her character was promptly given a similar injury to explain why she was wearing a cast.
 * Martin Sheen has limited movement in his left arm, which is why he puts on his suit coat with that characteristic flipping gesture. In the episode Two Cathedrals the younger Jed does it as well (the movement is used to link the two time periods), so I guess it's a very obscure example of this trope.
 * In Star Trek, Scotty's scenes had to be blocked around James Doohan's missing middle right finger, shot off during the storming of Normandy.
 * Especially odd, as the Nitpicker's Guide thought, because a) Scotty is an engineer, and presumably at legitimate risk for a hand injury from a mechanical accident, and b) one episode actually featured him getting shot in the hand by an energy blast, which could easily have been used to explain losing a finger!
 * In Deep Space Nine, Jadzia Dax got injured in a ship crash, in order to keep her lying in a cave recovering. Her actress had a skin condition preventing her from spending much time in the sun.
 * The same skin condition prevented her from being heavily made-up, but when an episode called for some of the crew to go undercover as Klingons instead of keeping Jadzia off the station for some reason, she simply wasn't picked for the mission (despite being second only to Worf in Klingon knowledge).
 * Garak suffered from acute claustrophobia. This is because his actor suffered from the condition to such a degree that even wearing the Cardassian make-up could be a trial for him. In one two-part episode, Garak spends much of the plot inside a cramped space: unsurprisingly, it's also the episode that reveals he suffers from claustrophobia (although the condition had been hinted at earlier points in the show).
 * Angel was confined to bed by a nightmare-demon-parasite thing in the fifth-season episode "Soul Purpose," then turned into a puppet four episodes later in "Smile Time" as David Boreanaz recovered from knee surgery. Even still, they framed several episodes to have Angel constantly sitting in his chair or otherwise leaning against his desk just to give David a break. (Unable to stand or walk much, Boreanaz contributed by directing "Soul Purpose," his first TV director's credit.)
 * Alexis Denisof was stricken with Bell's palsy shortly before shooting the first episode of Season 5. Most shots with Wesley showed only the non-paralyzed right half of his face.
 * Although Joss Whedon maintains he wanted to kill off an "opening credits" character early in the first season from the beginning the decision for it to be was made due to the actor's ongoing problems with drugs making him impossible to work with. He was going to be written into the last season (according to fifth season DVD commentaries), but due to the actor's death, the role was rewritten to bring back another fan favorite  instead, who uses the original character's name as a disguise.
 * Cynthia Watros (Erin on Titus) broke her leg and they wrote the event into the storyline, saying that she stumbled trying to chase a burglar down. They even made it into a clever character moment when Papa Titus commented that she hurt herself running after a burglar, instead of running away from him.
 * On Mash, Gary Burghoff (Radar) was always carrying papers in or otherwise hiding his left hand to cover up the fact that it's been deformed since birth.
 * In Yes Prime Minister, Jim Hacker spends 99% of his time sitting. This is because Paul Eddington had T cell lymphoma. It was so well written no one twigged.
 * The season 8 CSI: NY episode "Crossroads" had Mac Taylor sitting down for most of his scenes. This is because Gary Sinise tore a muscle during filming shortly before.
 * The Starz's production of Spartacus had to completely revamp the plans for the second season when the lead's actor was diagnosed with non-Hodgkin's lymphoma. The producers decided to make the second "season" a prequel miniseries, framed with earlier footage from the final moments of the first season to give themselves time to try to figure out what to do.
 * News reports from the studio seem to indicate that they'll be going The Other Darrin route to deal with the problem, replacing the lead (with the original's blessing) and continuing the plotline from the climactic (cliffhanger) ending of the first season.
 * Gale Harold was injured in a motorcycle accident shortly after joining the cast of Desperate Housewives as Susan's new boyfriend. The producers were quick to proclaim that they wouldn't let it interfere with their plans for the couple, and he will be back working on the show as soon as possible.
 * Which apparently meant his character moving from the neighborhood and Susan breaking up with him over the phone.
 * Kathryn Joosten's character was given lung cancer after the actress' long dormant cancer returned. Naturally, the scene where she emotionally reveals this to Susan is quite a Tear Jerker.
 * On Farscape, Jool got some feces in her eye and had to wear an eyepatch for a couple episodes after the actress had an allergic reaction to her makeup that caused her eye to swell for a few weeks.
 * In the early 90s, the soap opera The Young and the Restless had to do some fancy shooting to conceal actor Peter Bergman's severe facial bruising, brought on by a fistfight with his co-star Eric Braeden.
 * The first chief medical examiner on The Closer, Dr. Crippen, made several appearances in a wheelchair when actor James Avery injured his foot.
 * In Jerry Orbach's final scene on Law and Order: Trial by Jury, everyone is whispering outside a courtroom. The scene had been rewritten to accommodate Orbach's sudden loss of voice during shooting.
 * The voice loss came as a result of chemotherapy for cancer that eventually killed him. This was handled as Orbach's character saying he was retiring (which, considering he was sixty-nine at the time, is entirely believable).
 * In Hogan's Heroes, Robert Clary (Lebeau) always wore long sleeved clothes to cover up the serial number he had received in childhood at the concentration camp of Buchenwald
 * Had to be avoided in Highlander the Series as most of the characters are immortals. The actor who played Methos broke his wrist during the filming of an episode and had to take the cast off for his remaining scenes. His hand was also made up so the bruise wouldn't be obvious on screen.
 * And of course Joe Dawson, like his actor, had lost both legs. Oddly one never thought of Joe as handicapped, he simply had a peculiar walk.
 * Ander's coma/hybridization in the last half-season of Battlestar Galactica was written in after the actor was involved in a car accident so serious that it was initially unclear whether he'd walk again.
 * As Doctor Who was a long running series there were quite a number of times when rewrites had to be made.
 * Frazer Hines' character Jamie had to be recast with actor Hamish Wilson for episode 2 of "The Mind Robber" due to Frazer Hines having contracted chicken pox. Luckily the surreal nature of the story allowed an easy script addition and the temporary recast.
 * In "The Three Doctors", the First Doctor only appears on a video screen, recorded at Ealing Studios (not his home as legend has it), as William Hartnell was seriously ill and at times didn't remember he'd played the Doctor. He died two years later.
 * During filming of "The Pirate Planet" Tom Baker's lip was bitten by a dog, so in story the Doctor hit his face on the TARDIS console.
 * Due to Christian Kane's insistence on doing his own stunts whenever possible (and not always getting them right), his character on Leverage occasionally has to explain away the actor's injuries. Since Eliot is the team's fighter, it doesn't distract from the plot.
 * On one occasion, the actor had a bruised face from playing football in a parking lot - the character is questioned about it until he snaps "Well, how was I supposed to know it was a lesbian bar?"
 * A very humorous twist on the trope occurred during the second season of Saturday Night Live when Chevy Chase was hospitalized after an injury sustained during one of his pratfalls. Since that was a common running gag used to start the show, he called from his hospital bed and had Gilda Radner move the phone and push it over the desk, thereby completing a long-distance pratfall.
 * In an early sketch in another episode Guest Host Buck Henry was injured when John Belushi accidentally hit him in the forehead with his sword during a Samurai sketch. During the commercial, Henry's wound was cleaned and bandaged. As an in joke, all the other cast members from that point on sported similar bandages on their foreheads, and the incident was written into the "Weekend Update" sketch ("Up next: A deranged John Belushi attacks actor Buck Henry on live comedy program!")
 * Lucille Ball injured her wrist in a skiing accident, causing her Here's Lucy character to suffer the same fate for a few episodes.
 * Timothy Odmundson was riding his bike to the set of Psych when he fell and broke his collarbone. This prompted last minutes rewrites, Buzz being called in to do Lassiter's lines, and Lassiter showing up in a cast and refusing to say what happened. This injury persisted until the end of the season. In a deleted scene, he reveals to the Police officers that he had slipped and fell in his bathtub. That was NOT what they were asking about.
 * Timothy Odmundson also writes a blog and tweets in-character for Lassiter. Lassiter had an entry on new years resolutions, he mentions "not riding bikes."
 * Criminal Minds: Episodes in the 5th season had to be modified because two of the main actors -- Shemar Moore (who plays Derek Morgan) and Matthew Gray Gubler (who plays Spencer Reid) -- both suffered significant leg injuries. There was a temporary but noticeable absence of the usual Derek-in-action shots (e.g., kicking down doors, tackling suspects), while the 5th season premiere had Reid get shot in order to explain away his crutches or noticeable limp for most of the season's episodes.
 * An unusual reversal of this trope happened recently in British soap opera Coronation Street. The character Sally Webster had a storyline where she battles breast cancer. Turns out that the actress who plays her, Sally Whittaker, discovered she had breast cancer as a result of researching the storyline for the role. She says that she would never have noticed if the storyline hadn't been given to her, so the show effectively saved her life.
 * Actor Robert Guillaume's real-life stroke was written into a late season one plot line for Sports Night to explain the actor's absence (and later return while still undergoing therapy).
 * During the 'My Musical' episode of Scrubs, Judy Reyes, the actress who played Carla, had a fractured pelvis, limiting her to sitting down parts; for example the choreography for one song involves her being pushed around in an office chair. The exception, For the Last Time, I'm Dominican, was filmed two months later.
 * Near the end of the fourth season of Everwood Bright is seen wearing a sling for five episodes with the explanation being that he broke his hand in a failed attempt to karate chop a piece of wood in half. In reality, actor Chris Pratt sliced a tendon in his hand while cutting apart frozen elk steaks.
 * Wiseguy. When actor Ken Wahl broke his ankle in an on-set accident, this was written into the arc as the protagonist being hit by a cab (explaining the limp), then subsequently having his leg broken by loan-shark Johnny "Coke Bottles." A Suspiciously Similar Substitute character (OCB agent John Henry Raglin) was then brought in to replace Wahl for the Garment Trade arc.
 * RJ Mitte who plays Walt Jr on Breaking Bad has Cerebral Palsy as does his character. However he had always been written as having the condition. However, Mitte's palsy is far less severe so he had to alter his speech and learn to walk with crutches.
 * Stephen Tobolowsky broke his neck before filming the episode his Heroes character Bob Bishop got killed. As a result, in the episode Bob's always sitting in a chair, looking face forward.
 * Horse-riding fan Kaley Cuoco managed to break one of her legs in a riding accident during production on 8 Simple Rules AND The Big Bang Theory; this is why she spends a few episodes of the former wearing a cast and why she... doesn't appear at all in a few episodes of the latter. When she returned, she spent several episodes working at the restaurant as a bartender rather than a waitress so she wouldn't have to walk around.
 * In a variant of this trope, the 28th season of Jeopardy! began with host Alex Trebek staying at his podium for the whole game. This is because he tore an Achilles tendon during the summer while chasing a would-be burglar out of a hotel room during the summer.
 * The Andy Griffith Show's later seasons accommodated the stroke of the actor who played Floyd the barber, writing his scenes so he could sit down.
 * Wheel of Fortune host Pat Sajak came down with laryngitis back in 1996, forcing him to switch places with Vanna White to turn the letters for a whole week.

Radio

 * Kryptonite was first introduced because the actor playing Superman had a cold, or something like that...
 * When one of the actors who portrayed the Lone Ranger was killed in a car accident, a scenario was written up where the Lone Ranger was ambushed and injured and putting Tonto in the lead while the hero recuperated (and the studio could hire a new Lone Ranger!)

Theatre

 * Averted in the 2009 performance of Nemuri Kyoshiro. Gackt's training for his role as Nemuri Kyoshiro was so severe that it tore the soles of both of his feet. Even so, he continued to perform in the play as if nothing was wrong.
 * Sarah Bernhardt, considered one of the greatest stage actresses ever, continued to perform after she had one leg amputated, in 1915. She found prostheses unsatisfactory, and continued acting in pieces written to be staged with her sitting most of the time. She had such box office draw, that people still flocked to see her.

Web Original

 * During the filming of the The Nostalgia Critic's review of Alone in The Dark, the Nostalgia Critic developed a throat infection that made him almost inaudible. To compensate, he claimed that the movie was so bad that it had caused him to lose his voice and did his part of the review using a text-to-speech program. It actually came out even funnier.
 * Similarly, when he lost his voice during The Good Son review he did the entire review with subtitles for the footage and Talking with Signs for himself.
 * Happened again, causing him to postpone an update and instead do a brief sketch in which Ma-ti encounters Doug's character from Ask That Guy With The Glasses (who does not speak for the duration).
 * Spoony put his injuries to good use. His E.T. video game review was done while he was on painkillers and recovering from dental surgery, making his seeming madness more realistic.
 * He also had to concentrate on doing vlogs and Lets Plays for a few months after suffering a Jones fracture. This was caused by nothing more than setting his foot down wrong, giving him something of a reputation for having fragile bones. Ironically, Spoony's commentary for Kickassia reveals that he was pretty much the only person (including cameraman Rob Walker) who got through the arduous shoot unscathed.
 * Pushing Up Roses didn't sleep well before driving with Paw Dugan to Todd in the Shadows' house to film the Head review. As she didn't want to show her eye bag-heavy face on camera, the trio was shot with their backs at the camera, Mystery Science Theater 3000-style - and they admitted it worked well.

Western Animation

 * The Hey Arnold episode "Gerald's Tonsils" was created when Gerald's voice actor hit puberty. Rather than replace him with another boy (or a grown woman), they simply gave his character tonsillitis to explain the change in voice.

Film

 * A Film Within A Film example: In La nuit américaine by François Truffaut there is a scene where the film crew overviews a footage and then they suddenly realize that the (previously unnoticed) pregnancy of an actress will become more and more visible as the shooting progresses. Then they decide to make the character pregnant as well, although some of them complain that the viewers could make some unfortunate assumptions about who is the father of the child.
 * In the 2005 version of War of the Worlds, Miranda Otto played the remarried ex-wife of the hero, and nearly backed out as she was pregnant. Steven Spielberg convinced her to stay and worked her pregnancy into the story.

Live Action TV

 * Phoebe on Friends chose to become a surrogate mother for her little brother because Lisa Kudrow became pregnant.
 * They also averted it on the same show; when the current Romantic False Lead got pregnant near the end of her part on the show, they simply had her making phone calls in bed, where her pregnancy wasn't visible.
 * One notable example of this came in Star Trek: Deep Space Nine. A plot line had been started about Keiko O'Brien's pregnancy. Somewhere along the line, Nana Visitor (Major Kira) got pregnant with the child of co-star Alexander Siddig (Dr. Bashir). To cover, the writers created a shuttle accident that forced Bashir to transplant Keiko's baby into Kira's uterus. There was even a bit of Lampshade Hanging on the subject -- in a later episode, an irate Kira tells Bashir that her situation is his fault.
 * Gillian Anderson's maternity leave took the form of Scully being abducted by shadowy government forces (or aliens, or some combination of both, depending on which back story is more convenient for the episode you're currently watching), an event that completely reshaped the future of The X-Files.
 * On Frasier, Jane Leeves's first pregnancy (in 2000) was not possible for writers to work in to the plot, as it happened at the very beginning of her long-awaited relationship with Niles. They instead created a plot about her gaining weight uncontrollably and taking a sabbatical at a health retreat to combat the problem. Her second pregnancy (in 2003) was however written into the plot, as her character Daphne gave birth in the Grand Finale.
 * Meredith Baxter Birney's pregnancy was written into Family Ties but she still had to take several episodes off. The excuse provided for Elyse's mysterious absence was her doctor had ordered to stay off her feet. The producers tried several approaches for distracting viewers from her absence, including bringing on Geena Davis for a two episode run.
 * Due to Charisma Carpenter's pregnancy, her character Cordelia was mystically impregnated (for the second time!) in Angel's fourth season.
 * Joss Whedon really went above and beyond on this. Not only did he work Charisma's pregnancy into the plot, but he made it so that everything that had happened since the first season led up to it!
 * Earth 2 's final episode saw Devon Adair (Debrah Farentino) collapsing from an unknown illness and being put into cold-sleep until a cure could be developed. Meanwhile, Farentino was pregnant.
 * When Jennifer Garner got pregnant, her character on Alias did the same, with the result that Sydney's action scenes had to be cut considerably.
 * In yet another Stargate SG-1 example, Amanda Tapping (Lt. Col. Samantha Carter), was either pregnant or had recently given birth at the beginning of the show's ninth season, and so the character was reassigned to work at Area 51 and not the SGC. It's hard to think of a good reason for "Black Widow" Carter getting pregnant.
 * Vaitiare Bandera, who played Sha're, Daniel's wife, in the first few seasons of the show, was heavily pregnant with Michael Shanks' child when it came time to bring the character back. The writers managed to turn the child into a huge plot point for the next couple of seasons.
 * Claudia Black (Vala Mal Doran) also got pregnant around the time of the end of the same season, but it was an unintentional subversion of the trope: they were already planning on a story that involved her getting pregnant so they were happy they wouldn't have to use special effects for it. The character's daughter is very, very evil.
 * In Stargate Atlantis, Rachel Luttrell (Teyla Emmagan) became pregnant too. This also got written into the plot and involved her character getting pregnant via her unseen boyfriend and then her later kidnapping by Michael, a Wraith that the Atlantis team made somewhat human against his will. After he was born, Michael kept trying to kidnap them, turning her into a woman in distress instead of her previous Action Girl.
 * The original example: Lucille Ball became pregnant during her time on I Love Lucy. Her pregnancy was written into the show, at the time considered a risky and controversial move, as they weren't even allowed to say the word "pregnant" on American TV in the 50s. Interesting fact: that show popularized the use of the euphemism "expecting," and the episode in which Lucy gives birth broke the record for viewership up to that point.
 * On Married... with Children, Katey Sagal, the actress who played Peg, became pregnant, and the show's writers worked it into the storyline by making Peg pregnant, much to Al's chagrin. Most of the plot lines of the sixth season centered around the pregnancy, until Sagal's tragic miscarriage forced the producers to backtrack. The pregnancy was explained as being a dream Al had. The second time Sagal became pregnant, the writers had Peg return to Wanker County to try and reunite her divorced parents, and then set out to find her missing father. When Peg did appear, she was shown sitting in the backseat of a limousine, or talking to her family on the phone, or other situations that filmed only the top half of Sagal's body. When Sagal was ready to return to work (thankfully, her pregnancy was successful this time), an entire episode was dedicated to Peg's return.
 * Marcia Cross had to leave Desperate Housewives during the third season after becoming pregnant with twins and being put on bed rest. This was explained as her character Bree and her new husband finally taking their honeymoon, which had been delayed by the husband's being suspected in a murder case, the major story arc of the season. This meant the writers had to wrap up that mystery earlier than planned, basically leaving them to stumble through the rest of the season without any kind of ongoing story. Rather amusingly, Cross was able to return, with Bree revealed to be pregnant and Cross wearing a prosthetic. At the end of the episode it was revealed that Bree was wearing one too, as she was covering for her knocked up teenage daughter. Cross had said in interviews that she would love for her pregnancy to be worked into the show, as the storyline with Bree's daughter had already been planned so they would just need to change the person, but the writers decided against it.
 * Anna Belknap was pregnant during Season 3 of CSI:NY, so the writers gave her emotional problems so that she could put her relationship with Danny on hold and leave every crime scene - Lindsey couldn't deal with distraught mothers because 3 of her friends had been shot 10 years ago and she survived. (She mostly stayed in the lab where all shots could be head and shoulders or behind a table). She then left for 4 episodes to testify in the trial of a guy they caught for it. When she became pregnant for a second time, it was written into the show as Lindsey being pregnant with lover Danny Messer's baby, eventually leading to their marriage and the birth of their daughter Lucy.
 * Law and Order Special Victims Unit: When Mariska Hargitay got pregnant, Olivia was sent undercover with a green protest group while Temporary Substitute Dani Beck (played by Connie Nielsen) showed up to cover for her.
 * Law and Order: Criminal Intent had Alexandra Eames get pregnant at the same time Kathryn Erbe was. The storyline was that Eames was having a surrogate child for her sister. Another Temporary Substitute, G. Lynn Bishop, was brought in, but unlike Beck no attempt was made to give her any meaning; it almost seemed like they were writing her to intentionally be disliked.
 * Captain James Deakins got Bell's palsy at the same time that his actor Jamey Sheridan did, and wore an eyepatch for a good portion of his appearances.
 * Hilariously lampshaded in The Nanny when co-star Lauren Lane became pregnant. As there was no realistic way to work in a pregnancy with CC, the actors and directors simply ignored it completely, and utilized increasingly overt and bizarre ways to "cover" her pregnancy as it advanced (insanely huge bunches of flowers, co-stars standing in front of her with vases, etc).
 * They then explained CC's absence during Lauren Lane's maternity leave by showing CC going insane and being institutionalized.
 * Lampshaded and Played for Laughs in one scene where CC is talking about this trope, mocking how TV shows try to cover it up with such things as oversized vases...while holding an oversized vase in front of her.
 * Similarly, during Dianne Farr's first pregnancy on Numb3rs, they simply hid it for as long as possible. This was referred to by one recapper as using "pregnancy folders" and later "pregnancy furniture."
 * Alyson Hannigan's pregnancy was handled quite efficiently in How I Met Your Mother. Barney tells her a (supposedly) mind-bogglingly dirty joke..."And we didn't see Lily for four weeks."
 * Cobie Smulders alias Robin Sherbatsky was pregnant at that time too, but putting the only two lead actresses on the bus would be a little suspicious.
 * Also, Smulders, unlike Hannigan, is very tall, so keeping Robin in the booth as much as possible and dressing her in suit jackets proved sufficient to keep her bump from being obvious. They went through the same hoop-jumping with Lily (having her holding large objects or playing the guitar for her students on many occasions) but teeny-tiny Alyson Hannigan blew up to the size of a house (which is quite hard to miss in "The Front Porch") and evidently they gave up.
 * Hannigan did film a scene late in her pregnancy... of Lily winning an eating contest.
 * Poppy Montgomery of Without a Trace was a trickier example than most since her character Sam not only was not in a relationship, but was implied to be more or less Married to the Job. Utterly fearless, the writers had Sam conceive from a one-night stand with a bartender, and for the last two seasons of the show the plot was wrung for drama and Ship Tease.
 * When Roseanne actress Laurie Metcalf became pregnant, it was originally going to be covered up. Jackie's clothes got looser and looser (which was a huge tip off as she usually wore form-fitting outfits) and she always seemed to show up carrying something in front of her. However, as Metcalf progressed she got so big it couldn't be hidden any longer. Her pregnancy was written into the show about halfway through her real one.
 * In Jekyll Fenella Woolgar was cast as one half of a lesbian couple; however, by the time filming started she had a rather noticeable bump. She thought that she'd lose the role but it was no matter to the writers; they just worked it into the plot and it actually spawned quite a few endearing and funny bits. It was joked about on the commentary: 'You just can't cast lesbians these days!'
 * Leverage actress Gina Bellman was pregnant during filming of the second season. For this reason, her character left to "find herself" and was temporarily replaced with another grifter
 * Grayza's outrageously massive (and tattoo-decorated) pregnancy in the Farscape Wrap It Up "The Peacekeeper Wars" was because Rebecca Riggs had decided to have a career break and a child when the show was cancelled. Considering that her character had raped the hero in the previous season, this led to much Wild Mass Guessing about the in-canon paternity of the offspring...
 * Grayza's outrageously massive (and tattoo-decorated) pregnancy in the Farscape Wrap It Up "The Peacekeeper Wars" was because Rebecca Riggs had decided to have a career break and a child when the show was cancelled. Considering that her character had raped the hero in the previous season, this led to much Wild Mass Guessing about the in-canon paternity of the offspring...