My first son had a 40cm head circumference at birth - given it was a c/section - due to other reasons not size - I'm not surprised that it was bigger than possibly a natural birth due to the differing shapes they get as a result of the birthing process but his head has continued to be way off the charts. Also at birth his side and rear cranial plates were almost completely fused thus movement of the skull would have been minimal during the birthing process (or so I was told).

I suppose my question is I know it's possible to easily give birth to 10lb's etc but when there head is 40 cm circumference, the majority of the length from front to back, would that be considered a lot more difficult near impossible for the average person.

I reiterate that the c/sect was not due to size (rather that he was breach) and his head size had never been mentioned as a concern prior to birth - it was just one of those things after the fact that makes me reflect and wonder whether he could have come out naturally anyway given it's size and shape

Sorry for prattling