I've often complained about how pregnant women are given all kinds of conflicting information and told not to do all kinds of things, even when the evidence against such things is dubious. There seems to be an all-or-nothing approach to pregnancy dangers, which makes it hard for pregnant women to engage in any activity without feeling guilty or anxious (I suppose it's practice for new motherhood.) However, even I was pretty floored by a new study by the London School of Economics that says smoking during the first four months of pregnancy does almost no harm to the baby unless it is combined with other factors, and even after the first trimester the impact on birthweight is negligible. Um, excuse me?

The study looked at birthweight, and the researchers basically said the greatest risks are to women of low socio-economic status, who combine smoking with poor diet and alcohol. They add that for middle-class women who smoke during the first four months of pregnancy, there is little risk to the fetus, and even after there is a very small effect on birthweight. Low birthweight is linked with developmental problems and mortality. One immediate criticism of the study is that smoking is also tied to other problems like miscarriage, SIDS, and respiratory problems, and the study didn't address this.

Of all the things in the world, few are tied so clearly to serious health problems as smoking, so I'm totally skeptical of this one. And before anyone launches into an account of how their mother smoked like a chimney during pregnancy and they are just fine, I should add that almost no study offers a guarantee of destructive health effects, but that doesn't mean risks don't exist for a large percentage of the population.