Air Pollution Influencing Fetal Growth?

Mothers-to-be have enough to worry about when it comes to maintaining a healthy pregnancy--food, emotion, weight gain, and more. Now, consider yet another concern: air pollution. Researchers from the University of Queensland in Australia are reporting in the journal Environmental Health Perspectives that exposure to air pollution during early pregnancy could affect fetal growth in mid-pregnancy. They report it's the first study to measure these effects during pregnancy, rather than measuring only actual birth weight. You can read their report here.Scientists collected data from nearly 20,000 ultrasounds of pregnant women who lived within a few kilometers of air quality monitoring sites in Queensland. Here in Louisville, air monitors are often sited near where pollutants like ozone and nitrogen dioxide (NO2), among others, are being produced--think chemical factories, power plants. (I'm not sure exactly where the Queensland monitors were placed, but they measured the same kinds of pollutants.) Armed with the data from ultrasounds - including a fetus' head and abdomen circumference and leg bone length -- as well as daily data from the air monitors, scientists began plugging those numbers into statistical models, looking for correlations. They took into account air temperature and season, as well as how close the pregnant woman lived to the monitor. And they did find significant correlations between how long a woman was exposed to air pollution and decreases in a fetus' size.For example:"...all pollutants except [nitrogen dioxide] were associated with reductions in abdominal circumference. Based on the premise that the fetus accrues most body fat during the second half of pregnancy, the negative effects on abdominal circumference early in pregnancy suggest that ambient air pollution may interfere with the development of internal organs (e.g., the liver), as abdominal circumference is a proxy measure of the size of these organs (Ville and Nyberg 2003)."Yikes.The researchers point out the limitations of their study. They don't know, for instance, whether or not a fetus affected by air pollution can make up for that lost growth late-term. And they don't quite yet understand exactly how air pollution affects growth. But new details are emerging all the time about how pollution affects our health in general. I, for one, find each layer of revelation just a little chilling, as in, what will we learn next?