I'm sorry to disagree with those who said you need to give the dog plenty of attention to avoid jealously with the baby.
Is actually quite the oposite, you have to start ignoring your dog more well before the baby arrives, because you are not going to have enough time to continue with such level of attention once the baby is here.
We have two dogs who were our "babies" before DS arrived, they were very predictable and good natured, one of them was a bit bouncy but being a Yorkie it was not that bad. Anyways, we hired a dog trainer to prepare them for what was comming, what she said was the following:
-Stop allowing the dog into the rooms he won't be allowed to once the baby is here. That helps him not to link the baby to the new rule.
-Don't allow your dog to jump, it may hurt your unborn baby and can definitvely hurt a new born. She asked me not to allow the dogs on my lap anymore (maybe not your problem having a big dog!), as they may spontaneously jump in when I had Ds on my arms.
-Increase gradually the time the dog spends on its own, like leaving him in the garden for longer but with good stimulating toys. She said I needed to make time for the baby in preparation for his arrival.
-and in general, establish a strong hierarchy, letting the dog know he is the last one in the queu: Never allow the dog to pass a door treshold before you do, don't allow him to sit higher than you (like in the stairs, back of the sofa, etc), always feed him after you have finished eating and never ever allow him on your bed.
My dogs have done brilliantly, but if they hadn't I would have rehomed them, no doubt.