I would think that having a puppy and a new baby at the same time is not good. There are a variety of books that compare the different breeds and rate their compatibility with children. I would suggest a lot of research. I know that as much as I love my dane and my mastiff, I would recommend neither breed for those with small children. I wouldn't worry about an attack, but both breeds have tails as thick as broomsticks and they are face high on a toddler. They wag a lot too. Also the larger breeds can hurt a toddler just by running into them. I would stay away from the smaller breeds since a small child can do them serious damage. Rather than focusing on a particular breed, get a book that reviews all the breeds where you can pick and choose.
I recommend this one
"The Right Dog for You" by Daniel Tortora $10.40 at Amazon. Amazon is running a special where you can get that book along with "The Perfect Match : A Dog Buyer's Guide by Chris Walkowicz" for about $23.00. That isn't a lot when you consider the decision you'll be making and what you'll have to pay for a good dog. BTW, stick with a reputable breeder and a pure bred dog. The temperments are far more predicatable and that is very important when you're mixing kids and dogs.