There's a lot of this sort of information held at the Public Records Office, Ruskin Avenue, Kew, London, UK.

With your case, it may be that the baby was first brought ashore at NO, and was christened there, rather than born.

Death in childbirth was common enough on land, imagine the conditions on board a ship!

If you want a good read about ship conditions (albeit on a prison ship) try reading a book called 'The Floating Brothel' by Sian Rees. It follows the trip made by 'The Lady Julian' prison ship going to Sidney, Australia and is very informative.

LTS