When I bred several years ago, a cousin of mine said exactly the same thing, took the pup just after the baby arrived,two weeks later he had to bring it back as they couldn't cope, luckily for me I had another home for the pup.
Also, with the life span of a dog, if they got it now, the dog would probably die about the time that the child was at a very important time in their lives.
I personally would think it best when the child is a toddler