Traditionally, there was the assumption in #Christianity that people who did not get baptized would not go into heaven.
And based on my readings of Austrian #folklore , the notion that newborn children might die without even receiving an "emergency baptism" by a midwife was a major source of trauma to parents, since even those innocent souls would technically not be able to get into Heaven. And folklore would fill in the gaps left by Christian theology.
For instance, some tales claimed that the souls of such children would be led into a beautiful garden by Perchta (one of the incarnations of the female spirit/goddess Hulda/Holda/Holle). There, they would play for all eternity, and even after Earth was destroyed on Judgment Day, this garden would remain.
There is even one tale where a "miracle doctor" promised to use his quackery to reanimate the dead infant for just long enough that it gets baptized - but instead, Perchta shows up and made clear that she has already claimed the child's soul.
In other, darker tales, these souls would transform into black night birds and accompany the Wild Hunt on their travels.
It's a fascinating subject, and shows how folklore spins its own narratives that go beyond official doctrines.