History Main / ImmortalProcreationClause

* In ''Literature/IncarnationsOfImmortality'', while serving as an Incarnation, one thing that is stopped is aging and, since reproduction is an aspect of aging (cellular meiosis), they are unable to bear or sire children. When they leave "office", the restriction is lifted. This causes one of the characters to be nearly the same age as her son, physically at least (she had relatives raise him while she was in office.)

* Amy Thomson said in [[http://io9.com/355206/amy-thomson-gives-good-alien an interview]] that "I believe that societies whose individuals have immensely long lifespans, must either have very few young, resulting in a stagnant, inflexible, rigid culture, or else they must place cultural limits on lifespan in order to have the cultural renewal of a younger generation." She chose the latter, so while both the Tendu and the harsels in her books can theoretically live forever if not killed... they don't. Harsels choose to reproduce and die in the act of giving birth to hundreds of nonsentient harlings, which [[BizarreAlienReproduction chew their way out of their mother's flesh]]. Tendu spawn in huge numbers throughout their lives, but they ''eat'' their nonsentient young, or otherwise are not concerned by animals eating them. Most adult Tendu select one nonsentient subadult and cause it to metamorphose into an adult which is then cared for and taught, and choose to die soon after this child/apprentice is fully mature; there are a few individuals who choose not to die, and then they are culturally compelled to leave home forever and metamorphose again, becoming sort of wandering judges/problem solvers. This is portrayed as more frightening than death. It's mentioned that there was a time when they did things differently and the ecology was absolutely swamped with Tendu, and there weren't enough resources for everyone.

* In the ''Literature/TideLords'' tetrology, the immortals cannot interbreed with each other (The union of an immortal egg and an immortal sperm would become immortal at age -9 months and thus never come to term), but they can and frequently have interbred with mortals (There are four entire ''species'' who are descended entirely from the mortal offspring of immortals). Said children are always born mortal, but [[spoiler: those children whose heritage makes them more than 50% immortal by genetics (Such as an immortal father and one or more immortal ancestors in the mother's line) can potentially ''become'' immortal]].

* The Tucks from Natalie Babbitt's ''Literature/TuckEverlasting'' cannot change; they don't age, they don't die. Mrs. Tuck was past childbearing age when she drank from the spring, so it isn't an issue for the elder Tucks. However, the eldest Tuck son got married in the years after they drank from the spring and before they realized its effects; he had children, but his wife eventually thought he'd made a DealWithTheDevil and left him.

* ''Franchise/TheWitcher''

* The immortals from ''Literature/TheCompanyNovels'', though [[spoiler: Mendoza manages to have children later on in the series. Very, very weirdly.]]
* ''Literature/TheCulture'' generally discourages having more than a few children but no one stops those who wants dozens. Given that they have unlimited resources it's not really a problem.

* ''Literature/CruelIllusions'': Magicans who take the immortality spell cannot have children, because their bodies are frozen at the age that the spell was cast. Hence, the biological functions required for conception and pregnancy will not occur.

** Played with for the vampires of the White Court, who are functionally succubi/incubi. They breed relatively often for immortals. There are at least five Raith children in the main household, [[spoiler:and the patriarch of this family is known to have killed many of his sons]]. White Court vampires ''can'' avoid activation by having their first sexual encounter with someone they love, which essentially kills the demon inside them and renders them mortal. In addition, Thomas implies that the females of the Court don't get pregnant unless they choose to. In ''Literature/PeaceTalks'' he indicates that it is very unusual for males to impregnate their partners [[spoiler:which is why Justine getting pregnant blindsided him and is confirmed in ''Literature/BattleGround'' to have been intentionally caused by the thing possessing her to manipulate Thomas]].

* In Aleksandr Zarevin's ''Lonely Gods of the Universe'', the HumanAliens from the planet Oll arrive to Earth [[AncientAstronauts in distant past]], escaping from a power-hungry official. They plant some seeds they bring with them to grow food, and the seeds of a salad plant known as ambrosia grow practically overnight. After eating a salad made from ambrosia, they suddenly fall ill and wake up young and immortal. Somehow, an alien plant has acquired entirely new properties on Earth. They make a few locals immortal as well and establish themselves as gods on the island. While the females who become immortal are incapable of conceiving a child, this is absolutely not the case for any immortal male who sleeps with a human woman. That is, in fact, the cause of the many hair colors modern humans have. The original humans all had dark hair, while the Olympians (yes, [[Myth/GreekMythology those Olympians]]; they also call their island {{Atlantis}} after Atl, their home country on Oll) are all redheads. Immortality can only be achieved through consuming a sufficient quantity of ambrosia, which withered and died soon after blooming. The Ollans have managed to dry and preserve some ambrosia leaves. One of them is awakened by a Russian man after centuries in stasis. In return, she gives him a full dose. However, he decides to only take half of it and keep the other half for later. The half only heals his grave wounds and extends his life but doesn't turn him young or stop his aging. Later, he gives the other half to the protagonist's friend, who has lost a leg during the Soviet invasion of Afghanistan. The leg grows back overnight.
* Straightforwardly stated in C.S. Friedman's ''Literature/TheMadnessSeason.'' The vampires of that book are only fertile when they subsist on a diet of ''willingly provided'' human blood. This is explained in-text as an evolutionary mechanism to keep them from reproducing in an environment that isn't willing to support new vampires. The Marra, as well, are subject to this. Energy beings who are not able to die but can also not create new Marra (or, if they can, they have [[TheFogOfAges forgotten how]]).

* The [[DifferentlyPoweredIndividual Others]] in the ''Literature/NightWatchSeries'' are fully capable of reproduction, but their children have just as much chance of being an Other as a child of two {{Muggle}}s (i.e., very slim). This is why many Others avoid having children, so that they don't have to watch them grow old and die. The Others aren't, technically, immortal, but even the weakest of them can enjoy several centuries of life. The most powerful ones tend to be thousands of years old and not look it. The vampires and werewolves are the exception, as they're able to "initiate" (i.e., bite) their children to turn them. However, vampires and werewolves are the lowers rungs of the Dark Others and are viewed at with little more than disdain. The Light ones see them as nothing more than beasts, while the higher Dark ones consider them cannon fodder. Additionally, they can only feed on humans with a license granted by the Night Watch. Doing so without one is punishable by death. Additionally, vampires can only have one child after being turned, at which point their reproductive ability disappears. Nothing of the sort is mentioned for werewolves, but then the author can't seem to decide if they're undead or not.

* Completely ignored in ''Literature/TimeEnoughForLove''. Many near-immortals live throughout the galaxy and reproduce like bunny rabbits, even if they're 20 centuries old. Their children may also be effectively immortal, depending on what genes they picked up and whether they have access to a rejuvenation clinic. They solve the overpopulation problem by continually colonizing new planets. Justified as reproduction was the entire ''point'' of the Howard Families. They were an experiment in human longevity that worked spectacularly well.
** It is worth noting that Tellus Secundus, the planet where the story begins, has an unusually high population of near-immortal "Howards" and in consequence has instigated population controls. The planet's chief executive mentions to Lazarus Long that he'll grant an exception to any woman Lazarus feels like having a child with. Lazarus himself is a special case as, being over two thousand years old and born at the start of the Howard experiment, he can claim over 80 percent of the galactic population and over 99 percent of Howards as his descendants to some degree or another.
* Averted in Wen Spencer's ''Literature/{{Tinker}}'' series. The Oni are immortal and breed like mice. Famines are common in the Oni's overpopulated world. The Elves on the other hand are just as fertile as humans but don't feel the need to have as many children since they are immortal. The population of Elfland has dropped by 50% over the last two thousand years due to war, accidental death, and suicide.

* ''[[Literature/TheTwilightSaga Twilight]]''

* Nathan Brazil, the immortal guardian of the universe in Creator/JackChalker's ''Literature/WellWorld'' series. Since it's not possible for anyone else to be immortal (you have to be programmed into the computer that stabilizes the universe) he considers not being doomed to outlive descendants a mercy.
* ''Literature/TheWitcher''

** Sorcerers are generally sterile after their training, though there are a few exceptions. [[spoiler: Geralt's mother, for example.]]
* In the short story [[http://www.gutenberg.org/files/21279/21279-h/21279-h.htm ''2 B R 0 2 B'']] by Creator/KurtVonnegut, medicine has conquered old age and death. The population numbers are kept under [[PopulationControl tight control]] to avoid resource overuse. This means you have to convince someone to volunteer to die in order to have children. The main character's wife is giving birth to triplets...
* In ''Literature/TheFolkOfTheAir'' series, faeries have an incredibly low birth rate and most households are happy to have one child ever. The current king having six children/potential heirs is almost considered to be vulgar. Characters also comment that despite the FantasticRacism faeries have towards humans, having [[MarsNeedsWomen human wives/consorts]] and [[HalfHumanHybrid half-human children]] in the family strengthens bloodlines and is why faeries haven't gone extinct.
* In ''Literature/SecondGenesis'' by Creator/DonaldMoffitt, the newly immortal humans have a cultural norm allowing one child per couple every hundred years.

* {{Inverted|Trope}} in the ''Literature/DoraWilkSeries'', in which nigh-immortal [[OurAngelsAreDifferent angels]] are ''insanely'' fertile, to the point where any sexual encounter, even with contraceptives, is nearly sure to result in woman getting pregnant.

* In the BleachedUnderpants manga that ''Manga/{{Hellsing}}'' was based on, Proto-Alucard explains that he kills off vampires who Turn too many humans because if there were too many vampires, there wouldn't be enough (read: ''[[ApocalypseHow any]]'') humans left to feed on. He bring this up in Chapter 1 of the actual series as well.

* ''Literature/{{Inkmistress}}'': Demigods like Asra will live for centuries more mortals. They're incapable of having children, which pains her greatly, as she would love to be a mother. [[spoiler:She gets her wish by another means, adopting a son.]]

* Vampires from Meyers's ''[[Literature/TheTwilightSaga Twilight]]'' were believed to be infertile, but it turns out that this only applies to the females. So the guys can still get it on with a human girl, but it's incredibly dangerous for the human woman.
** The same for wolves (though they're really only immortal so long as they shape shift). While there's only been one female wolf, she appears to have become menopausal after she became a wolf. The males can all still have children, a fact which is publicly known because of imprinting.