Unlike some animals, who need to spot their mother within seconds of the birth and form a kind of identity stamp of her so they can follow her around, it is the other way for humans. A human mother must see and be close to her baby immediately after the birth otherwise an instinct of mourning kicks in because the body assumes a still birth has occurred and then even if the baby is brought back within a couple of minutes, this process has already begun. Bonding and attachment to the baby can be difficult, leading to PND etc. Very interesting.
Sounds like a great book, will have to go check it out!