Baby born with a head the size of a 1-year old's?!

I have been reading a book called Birth by Tina Cassidy.

Birth: The Surprising History of How We Are Born

This book really is my first read on the history of childbirth. I am only on page 76 but already found some interesting bits to share.

In the first few chapters she describes how our evolution from apes to homosapiens has made birthing more difficult. Apes have a smaller head, a wider pelvis, and basically when giving birth the baby "drops down the chute" without too much difficulty. As homosapiens started to walk upright the body changed to a larger crania, a smaller pelvis, and a birth that requires the baby to rotate through the birth canal. This twisted journey takes a lot longer!

As brains have progressively increased in size over the last 2 million years we hit a wall in increasing the size of the pelvis to accomodate the head and had to start giving birth to more altricial babies. Altricial was a new word for me and it means helpless. Other primates' newborns are more developed than ours at birth as their brains double in size after birth while human babies' brain size quadruples. She explains how human gestation is described by some as 38 weeks in and 38 out of the womb. When human babies begin to crawl they are at the developmental level of a deer at birth.

Tina also gives a crotch ripping analogy: for a human to be born at the level of development of a newborn elephant (630 days of gestation), the child would be born with a head the size of a 1-year old! Auch!

She also explains our babies' fussiness as a sign of their altriciality and not being ready for life outside the womb or being overwhelmed by it. This makes sense to me and helps explain why babies love to be worn by the mom. They are still working on their 2nd stage of gestation outside the womb.

Anyone else read this book? Thoughts?