You can drink while pregnant and, as long as it’s done in moderation, everything is probably going to be ok. Or maybe it won’t be ok. Heavy drinking during pregnancy can cause serious health issues for the baby, and no one seems to know exactly how much is too much, so the current guideline is “don’t drink.” No drinking means no fetal alcohol effects. But it might also mean a miserable pregnant lady. And stress and miserableness can lead to a series of health issues as well, including miscarriage.
So, you know, back off a woman who just wants a glass of wine. Or the runny egg. Or the deli meat. Or the soft cheese. Or the tuna sushi. Or the cup of coffee. Life is a balance between risk and reward; maybe just put the best public health information possible out there, and let preggos decide for themselves what to consume and which risks are worth taking.
(Naturally this is 100% self-interested. I don’t plan on becoming pregnant anytime soon or perhaps ever, but if I found myself in that situation, you would be prying the occasional glass of red wine out of my cold dead hands. Also cheese).