The advice on this has changed several times in the last few years. Until about 5 years ago, the usual advice was that a small drink daily was OK, though getting drunk would always have been thought dangerous as the levels of alcohol needed to get drunk are too high.

Now, the guidelines have been tightened up as more studies have been carried out on the effects of alcohol on the health of pregnant women and their unborn babies. The most recent advice from the department of health is to avoid alcohol altogether in the first 3 months of pregnancy and, if you are trying to conceive, not to drink during that time either. This is because a foetus is at its most vulnerable in the early stages.

After that, it is believed that one or two units a week should be all right (eg half a pint of beer or a small glass of wine) but while the advice remains uncertain a lot of pregnant women feel safer if they just don't have a drink for the whole time.