If you drink alcohol (more than two units a day) there is an increased risk of cot death.
Use this calculator tool from the Drink Aware campaign to work out how many units you are drinking and how many calories that adds up to. http://www.drinkaware.co.uk/tips-and-tools/drink-diary/
Falling asleep with your baby on a sofa is very risky. Drinking makes you feel drowsy, so if you have had a drink and you're with your baby, be alert to this.
Don't sleep with your baby in your bed if you've had a drink because this increases their risk of cot death as you'll be less aware of your surroundings.
Really, it's best not to drink at all during pregnancy - and best to keep it to a minimum when you're around your baby!