In an especially nannying article, Emma Barnett, "Women's Editor" of the Daily Telegraph (do they have a "Men's Editor"?) has a go at pregnant women who have the occasional drink:
I am no fan of judgement. I think people are, by and large, a law unto themselves. Last month, however, I was at a dinner party in a painfully cool (both in temperature and temperament) East London warehouse when I noticed a friend’s eight-months-pregnant wife happily knocking back a bottle of beer. “Don’t stare Emma,” hissed my husband. “It’s just the one.” I silently scolded my horrible self. He was right. But then this successful lawyer moved onto the Pinot Grigio. Two great goblets of the stuff. And I found myself in full judgement mode.
Our writer transformed from a gentle, non-judgemental luvvie to a judgemental nanny in one short paragraph. She wheels out some doctor's estimation of the impact of drinking complete with the obligatory scary number:
Last week doctors revealed that up to 7,000 babies a year in Britain are showing signs of developmental damage because their mothers drank during pregnancy.
In 2012 there were 729,673 live births in the UK so, even at the upper end of Emma's unreferenced estimate, that's less than 1% of total births. Emma then goes on to quote some doctor pal who suggests having a glass of wine is worse than smoking! This doesn't seem to me, however much we should be concerned about those 'up to 7,000' children, that drinking in pregnancy is a major problem.
So what the evidence? The answer is best given as mixed. Some studies show a small negative impact of moderate drinking on birthweight but the most substantial studies really show no significant negative impact of moderate drinking:
The bottom line, according to study co-author John Mcleod, is that "[there's] certainly no evidence that moderate alcohol use by pregnant mums is good for their kids, and [there are] reasons to be cautious about other messages around 'benefits' of moderate alcohol use by pregnant mums. But equally, [there's] no strong evidence for important harmful effects."
So a sort of researcher 'meh' there - probably best not to drink but if you have the odd glass or two during pregnancy it's probably not having any harmful effect on the baby.
More recently a significant study challenges the prior consensus on alcohol affecting birth weight. This is a multi-national study involving 5,628 women who were pregnant for the first time between 2004 and 2011and it concluded that:
Rates of premature birth, babies with low birth weight or small size, and preeclampsia—a potentially life-threatening condition in which a pregnant woman develops high blood pressure—were similar across the alcohol consumption categories
The studies quoted above looked at child development after birth whereas this study only looks at the situation at birth. Again there appear to be few if any negative effects from moderate alcohol consumption during pregnancy.
It seems to me that the proper advice is exactly the advice given to mums now - go easy but if you're out don't feel that you can't have a glass of wine.