Dog is driving me nuts

I got a Dachshund awhile back and found out I was pregnant that same week. Every one told me to get rid of him. But i kept him and grew to love him during my pregnancy. He was almost fully potty trained before the baby came. Now that the baby is here it's another story. He pees everywhere. I am so sick of it. My husband thinks it's because he's trying to mark his territory. He pees near the baby's things. His carseat stays next to the door and he peed right next to it. He also peed next to the baby's jumperoo. Not on it but next to it. He's been peeing on our leather couch too. Idk what to do anymore. I leave the sliding door open in the back so he can go outside freely. I don't understand why he's doing this now. Would getting him neutered fix the problem?