The problem with alcohol is that we don't have sufficient data yet. The best we do have is a couple of large scale Dutch studies that seem to show that low consumption is fine. That's low as in a couple of units a week.
The complication comes from the fact that those studies are looking at the data on a population level (which is fine of course, that's a good thing!) as an individual, we all metabolise alcohol differently. Some of us have enzymes of steel and can operate on several glasses and others, like me, get squiffy after half a glass. Some of us have only one, or no copies of the alcohol dehydrogenase gene.
The foetus is differently sensitive at different times as well, so there will be phases of development where ingesting a specific substance such as vitamin a does no harm at all and others where it's catastrophic. Also the total amount is important. To get FAS you need to drink plenty and often, but fasd is a more subtle spectrum. Where do you draw the line? The answer is you can't, so you need to give women the data to make an informed choice. We also vastly underestimate our alcohol intake - one unit of wine is about 80ml, but a small glass is 125ml (and most servings these days are 175ml upwards) so it's really hard for people to know how much they are actually drinking. The rate of ingestion and food intake also affect your blood alcohol.
My own thoughts (as a developmental biochemist/geneticist by training) is that:
- Very low consumption is probably fine
- The first trimester is most vulnerable
- Women need solid data, not preaching or bullying
- Forcing abstinence is the thin end of the wedge to making us baby vessels, not competent adults.
I've not had any booze at all so far, but if I'm honest that's more down to nausea than anything else. I will definitely say yes to a low alcohol beer or cider in the summer and I'll probably have a little toast of bubbly at the wedding I'm off to next month.