I think part of the issue is that it is impossible to do a full clinical study on this which would involve 1000s of pregnant women imbibing set amounts of alcohol and analysing the results, discounting for other factors. For obvious reasons! That would really be the only way categorically to say what the boundaries are, and put a number to cause/effect. So instead:
a) we rely on self-reports, and most people will under-report through embarrassment. This won't be just FAS cases, but also the vast majority of people with healthy babies will say oo, I only had 1/2 a sherry on the last Thursday of the month, when actually that's a bit of a porkie. But therefore their reported intake gets classed as the safe one.
b) we also only really look at levels when something goes wrong. So, as per the first point, the Mum of a FAS baby will be questioned and admit to maybe 2/3 glasses a day, so that then becomes the danger point, when actually it may have been a litre of vodka. She won't want to tell the truth given things like the recent court case, baby being taken away etc. I've had 3 healthy babies and no one's ever asked me what I drank during pregnancy, which was obviously 'safe' (but, certainly in the first trimester, unbeknownst, a lot).
Don't really know what to do about this. Could MN maybe do an anonymous survey in which we all crossed our hearts and promised to be truthful? I COMPLETELY agree that FAS is awful, and people need to be educated. This is in no way to diminish the perils of large quantities of consumption during pregnancy. But the problem is the current scaremongering is preaching to the choir and just panicking and patronising women who're terrified and objectified enough as it is. And stress is also a big factor when it comes to pregnancy complications...