Blimey - this is a whole new arena for me. When I married my husband I knew he was an alcoholic at the time but knew very little of what alcoholism really was. However - despite our "dream" to have a child together I told him there was no way I was having a child with him while he smoked as much as he did - didn't want him dying of lung cancer and leaving me holding the baby! As the marriage progressed I realised that having a child with him was simply not an option, that the alcohol issue was even bigger than I first thought. The two children I already have from a previous relationship are my world - and they are the number one reason why I firmly put an end to the situation and separated from my husband.
On reflection - making sure that the "dream" of having a child together was not fulfulled, and that I never got pregnant, was one of the smartest things I did in that marriage and possibly the only truly correct reaction I had to his addictions (alcohol and nicotene).
You need to think really really carefully about this. Children change everything and they have no say about the situation they are born into.