For some reason health guidelines have recently been changed to say that expectant mothers shouldn't drink at all, despite there being no new research. It's up to you on the smoking and drinking thing, although if I was expecting I'd want to give my baby the best possible start by taking no risks with these things although I know it can be difficult to give up smoking! As for what you can eat talk to your doctor/nurse/midwife, they should all be able to give you some relevant advice!