What's that thing, the facts, about humans being one of the only species to give birth at the stage of gestation we do it at

[VictorianSqualorSquelchNSquirm]

and most other species giving birth when babies are more formed?
I read on MN once that if we walked on all fours we would give birth later to more developed offspring.

If you read Birth: A History there's some interesting stuff on this in the early chapters.

Isn't it to do with the human brain being too large so if we delivered our babies more fully developed the head would be too big? Being on all fours rather than walking upright would have allowed for a bigger head to be delivered I guess but maybe not big enough for the baby to be more independent.

Kangaroo babies are even less developed though

Hmm but wouldn't the birth itself be more than slightly more painful/dangerous for the mother if babies were born later??

It explains why some newborns can be so unsettled--they need more time 'inside'. I felt that with my son. He needed constant holding for the first month.

Yes it's the price we pay for walking upright. There's a trade off between being upright and having big brains (which are needed to be upright in the first place) - evolution is a wonderful thing.

Love the kangaroo thing, their live births are barely formed and the mother has to lick a path through her fur to the pouch for the joey to follow. They start out about the same size as the mother's teat - so need big mouths!

Head's are too big to wait any longer. And I remember some stuff about head's only being able to get bigger if humans could stand so they were cooler.

A bit off-topic, but some lovely footage of kangaroo birth and journey to pouch here

So if you were bedridden you would have a small head?

LOL Lady.

Engineering problem. Getting a baby's skull through a woman's pelvis requires the baby to be pushed out while the head's (just) small enough to fit.

Explains the high rate of birth complications in humans vs other primates.