Thanks for the replies. It's reassuring to know that most of you don't think IABU and that this behaviour isn't really on. He was trying to argue with me this morning and say that I am overreacting whereas now I am getting all the sorry it won't happen again messages and that he's under a lot of pressure with work etc. Obviously he has sobered up a bit!!
Just to clarify where I stand meringue and drinkygin - I'm not expecting him to stay sober in case something was to happen to me or the baby. Of course that would be ridiculous and completely over the top. I am saying that I am concerned that he gets so drunk he doesn't know where is, loses all track of time and doesn't get in contact with me so yes, if for whatever reason I needed to contact him or needed him for whatever reason which is unlikely but not impossible I wouldn't be able to get in contact. I have no issue with him going out and letting his hair down but to go out and not text or ring for hours on end or even give me the heads up that he won't be home until the early hours isn't fair in my opinion, not when you are a parent. I went out recently and had a great time with my friends and was out for the duration but I was in regular contact and had given lots of prior warning that I would be out and that I had a cab booked for 1.30am. It is very different to say is it ok to go for a drink after work and then roll in at 3.30am.
And yes I had to let him in last night as we have gates and he left his keys in his car and he had to buzz the intercom which woke the baby up.
He had his boss' retirement drinks recently and stayed in a hotel which was a relief to be honest as I knew in advance and knew I wouldn't have the worry of when is he going to be home, how is he getting home etc but it resulted in an argument, not because of him being out or getting drunk but because I didn't hear from him from 5pm until the next morning and again, I don't think that's ok when you have a young child.
I had the taxi idea before meringue and suggested he do this for his xmas do so he booked it for midnight and midnight came and went and he basically just didn't get in the cab and came home hours later. It was even more embarrassing because the taxi is a family friend so I won't be suggesting that again.
And drinkygin having a baby does tend to get in the way of going out and getting smashed for most people!