Good question, I was there for the birth of all my children, nothing exciting, nothing special, just a function of the human female body. But, my wife wanted me there, that is the important thing, it gave her some form of support.
If the husband is the father of that child I say absolutely without a doubt. If on the other hand they happen have meet after conception and married within that short period of time and the baby is that of another man it should be handled differently.
Then it is a matter that should be discussed and there should be a complete understanding well before the due date. It should be understood if yes he is or if no he is not.