WAG, I think many of us who have replied on this thread have had drunks in the past with young babies and I can promise you it is not pleasant and telling them to move to a spare bed when they are pissed does not work.
If he`s abusive and the op feels fearful when he is drunk then yes he needs to go, he will not change, he will come up with excuse after excuse as to why he get pissed, its already impending fatherhood next it will be the overwhelming responsibility then the lack of sleep etc etc.... There is nothing more frightening then if you are doing a midnight feed a drunk spouse wanting to take over and getting abusive when you say no. A hangover over one with hangover breathe is absolutly horrendous too, it use to make me sick to my stomach. You are always fearful the moment they start the first drink, if they are a little late from work, have they gone via the pub, etc.... It becomes overwhelming.
Writing these things brings no pleasure to any of us who have been through it, but I rarely comment on relationship threads but this one took me back 18 years to the hellish period of living with someone like that.
I know that some people might think that some of on here are over reacting and Im aware that the op says that this happens once a week, but that is once a week too much. I also see she has not come back to this thread, I totally understand this, its easy to deny what is happening, who wants to admit that their great partner actually frightens them when drinking? Pissing on the floor is not normal drunk behaviour, that is extreme, although, the penny must be dropping for the OP to post and hard as it is for her to read such negative things, hopefully shell see how many of us have been there and managed succesfully to move on from men like this.
OP, I can honestly say looking at my lovely, confident 18 year old dd I did the absolute right thing but not allowing her to grow up with a dad as a happy drunk. And yes, sadly I hear on the grapevine he is still a happy drunk. (having made a decision to not be in his dd life (thank god)).
I really really wish you and your baby the very best in the future.