I've got a lifetime of stories to tell about integrating my children and dogs (I have a total of 5 children, 4 of them are my flesh and blood). My youngest will be a year old in a couple weeks. Prior to his birth, my dogs had only been around my youngest daughter (now 5 yrs old) and the other children who range in age from 14 yrs old down to 9 yrs old and their friends and strangers at the parks/playgrounds. My dogs love children, even strangers. They are rambunctious and aloof, and high spirited dogs, but when it comes to children, they just know something and they calm right down.
My two oldest dogs, the black and tan mutt and the white and tan spotted APBT
in my signature picture had never been around a newborn, and I've had them both since they were pups. For probably the first two weeks after my son and I came home from the hospital, they barked, whined, howled and growled every time he cried. The way I got them used to him was first by letting them smell his car seat, his clothes, his playpen, stroller, blankets, towels, washrags, and myself after he'd been handled. Then, I started taking him to their kennels and letting them smell him through the kennel door; I would put his feet and hands up to the kennel doors, touching the door, so they could smell and lick. While doing so, I would softly tell them, "See the baby? Be easy, love the baby" and praise them for being calm, even though they wiggled so hard the kennels rocked lol.
After this, I slowly began allowing them out (one at a time) while he was in his playpen and letting them smell him through the mesh on the playpen sides. They would jump up and put their front paws on the rail of the playpen to sniff at him when he was in the bassinet part of the playpen, and I stood right there to supervise to make sure they didn't accidentally scratch him. I would let them sniff and lick at him, and then tell them "OFF" and gently push them down and guide them away to go do something else.
Once they settled down with this part of the introduction, then I would allow them out (again, one at a time), and have them on lead, while he was laying on a blanket or on the couch next to me, and allow them to check him out this way. If they got too excited, then I would lead them away and go do something else until they were calm again. After they remained calm on lead the entire time, then I began allowing them off-lead.
He's walking now (has been for a few weeks), and he goes into the dog room with me to feed and talk to them, and he visits each kennel and coos at them and sticks his hands in the kennels and they lick and wag their tails and love on him just the same as they do the older children.
The point to this story is, the success of bringing a new baby into the home with an older dog relies mostly on your ability as a handler/owner, and your trust in your own ability, as well as your trust in your dog(s). If you're thinking negatively, or worried about the unthinkable, then it's possible the dog will feed off this energy and react poorly. My old man's nervousness kept him from being able to handle the dogs with our son as a newborn, as his attitude has been the same all along... "If they hurt one of the kids, they will die." His apprehension and worry-some mentality is what caused him to not be able to introduce the dogs to our son, and vice versa. A little background, though, prior to our relationship, his only dealings with purebred APBTs was in his early 20s-30s, and he was bitten, so his idea of the breed was that they're all man-biting, baby-killing machines. It has taken the duration of our relationship for me to educate him on the breed and get him comfortable enough to allow not one, but two of these wonderful dogs into our family and to share our home. But, his attitude is the same, regardless of breed of dog when it comes to our children.
Anyways, trust yourself first, and then trust your dog during the integration of the new baby to the family. You'll be surprised! Best of luck, and we can't wait to see pictures of the new baby and your pup together!