Why Pure-Blood Baby Elf Is So Rare In The Witcher?

Season 2 of The Witcher featured more elves and delves further into their background and way of existence, showing that they have difficulty having children - but why? The Witcher is a series of novels and short tales written by Polish author Andrzej Sapkowski that became popular after being turned into video games, which helped it extend its already expansive universe. In Poland, The Witcher was converted into a film and a television series in 2001 and 2002, respectively, and it received its first English-language version in 2019, due to Netflix, where it soon became one of the site's most popular franchises.
Season 1 of Netflix's The Witcher took a different approach to Sapkwoski's storylines, following three people whose adventures are set in separate locations and times, with their fates eventually meeting at the season's finale. Geralt of Rivia (Henry Cavill), Yennefer of Vengerberg (Anya Chalotra), and Ciri (Freya Allan) continued to lead the story in its second season, now in a more linear and easy-to-follow timeline. Francesca Findabair (Mecia Simson), an elf sorcerer who acted as queen of the elves and as such aimed to keep her community safe, was one of the new characters featured in The Witcher season 2.
Francesca's pregnancy was a significant component of her storyline in The Witcher season 2, and it was through her that The Witcher season 2 showed that elves struggle to conceive babies. The Deathless Mother approached Francesca, Yennefer, and others, taking on different forms for each lady, and disguised herself as Ithlinne (a famed elven healer and oracle) in front of Francesca. Francesca was given the opportunity to reestablish the elven community by giving birth to a true elf, but she had to ally with Fringilla and Nilfgaard first. Francesca finally gave birth to a daughter, but she broke her promise to Fringilla, and her child was slain as a result. The birth of Francesca's kid was a significant deal for elves since it was the first time in years that a pure elf had given birth successfully, but why is it so challenging for them?
Elves live far longer than humans because, unlike humans, they think they were created, therefore they see humans as lesser. Elves' physiology differs significantly from that of humans, and despite living lengthy lives, they are only fertile when they are young. This is considered to be one of the elves' greatest flaws since they are easily overpowered by other races due to their lack of numbers. Because they can only conceive during their early years and because their biology makes it difficult for them to have children, the successful birth of Francesca's kid was such a significant occasion for the elves and one they had to rejoice. The advent of this pure elf infant gave society a lot of optimism because it proved that they could repopulate, but that didn't last long. Francesca's baby was assassinated to provoke the elves into fighting, and Francesca retaliated by murdering all the newborns in Redania that crossed her way.
With elves now playing an active role in The Witcher after Francesca learned from Istredd at the conclusion of season 2 that Ciri is alive and possesses elder blood, season 3 could ideally go more into their narrative and lifestyle, maybe answering topics that the novels haven't addressed. It's unclear if the elves in Netflix's The Witcher will welcome a pure elf infant into their tribe after everything they've gone through, but given that the series has already made several alterations to the novels, it wouldn't be shocking if the history of elves is altered as well.