I must agree that Thumper's concept is the most practical. The mother remains in a safe, alcohol-free place where the safety of the baby is assured as much as can be. Meanwhile, you get to prepare the nursery and rest up and get ready for baby coming home.
Once the baby is born and in YOUR care, Mom is free to make her own choices and you make yours.
I always prefer to keep things as simple as possible. That old KISS principle.