I had a pom many years ago, from the time he was 4 months old to when he died of cancer at 11 years. He was my first baby and I loved him! My children dearly loved him too.
That being said, I want to gently tell you here that part of the problem is what you have said in your request, that you treat him like a human and that he's super spoiled. I think it was a really rude thing for Teresa to say you've created a monster - there are nicer ways to point out the problem of treating a dog like a person, and everyone on this site needs to talk nice - but essentially, she is correct in that you need to treat him like a dog. Dog behavior is all tied up into where they stand in their pack. Dogs are pack animals, and your entire family is the pack. In a human family with a dog as a pet, the dog MUST be at the bottom of the ladder - even the children must be over the dog. It is your job to establish this. A human family should NEVER allow the dog to be alpha - that's the people's job.
First of all, do yourself a big favor and talk to a dog trainer, hopefully someone who has worked with poms. Ask around and find someone with good references. Buy a diaper harness for your dog at PetSmart and use your own maxipads in the harness - that's so much cheaper than buying what they sell. This will help you save your carpets while you figure out how to train him. If you don't have a crate, buy one and put him in it rather than letting him have the run of the house. Establish real parameters - think about what is going to be important when the baby comes. If you don't want him jumping on the furniture where the baby will be, you have to establish that now. Your trainer will help you figure out how best to accomplish that.
Before my first baby was born, my pom slept with me. I knew we couldn't have that after the baby came, so we had to nix that. Do that now - you don't want him to associate the baby with your throwing him out of the bed. At the hospital, they gave me a few caps and blankets for the baby - I sent home one of each that the baby had worn with my husband before I left the hospital so that the dog could smell the baby on them. As soon as I arrived home, we let the dog come up on my lap with the baby and my husband at my side, allowing him to sniff the baby. We talked very sweetly to the dog, sharing this important event with him.
This part is important, H.. Unlike another child you would want to spend time with while the baby was asleep, ONLY pay attention to the dog when the baby is awake. Talk to him and pet him and invite him to pay attention to the baby, and when the baby goes down for a nap, ignore the dog. It's hard for a few weeks when the baby sleeps so much, but it's really important for him to associate the baby being with you as when he gets loving from you. That way he looks forward to the baby being awake. If your trainer has had children him or herself, he or she should understand the importance of this. My dog responded well to this.
Later when my kids got a little bigger, my pom was so funny - he wanted to do everything they did. He wanted to ride in the baby carriage and slide down the playground slide. We handled this by allowing it; he realized he really didn't like either (can you imagine my husband taking a dog down a kid's slide! LOL!) and he didn't want to do it anymore. Allowing him to try meant that his competitiveness didn't morph into jealousy.
The last thing I'd like to say is that you must never leave the dog in the room alone with your child. Every dog expert will tell you this. Children are unpredictable and poms are little dogs with small bones. They are afraid of getting hurt and they will use their teeth. Dogs are also unpredictable - sometimes we just don't know why they do what they do. You must always let your dog know that any inapporpriate behavior with your child, nipping, baring teeth, growling, etc., is wrong. Your trainer will help you know the best way to do this. I never had that problem with my dog, but it does happen. You must be vigilant because poms are not generally known to be good with children.
All my best to you in having a positive outcome in how you manage the change in a family with the dog as a "child" to the dog dethoned by a real baby, and relegated to being a real dog. It is a necessary thing to do, H., for the harmony of the family and the safety of your child. Though hard right now for you to see the logic of this, your dog will actually appreciate it eventually, I promise you.