Honestly, your dog will get used to the baby, and your baby will get used to the dog. The first week or so will be full of barking/startled baby, but at the end the baby will sleep through the dog bark and the dog will be used to the crying baby.

Shock collars are generally harmless, but I don't really like punishing my dog for doing what comes naturally. To me personally, it's like punishing a baby for crying or a child for talking. It's how they communicate, and I hate the idea of stiffing that. That's just my personal feelings.. I'm not judging people who use the collars, or trying to make you feel guilty for it or anything. Personally, I would record a baby crying and play it for the dog, or just wait it out when you bring the baby home.

Here's a link to a product I found.. it's $14.50 and has 40 minutes of baby sounds. I haven't tried it, and have no idea how well it works. I just found it in a quick google search. Might be worth looking into.

Prepare Dog for Baby - Preparing Fido