A number of studies have come out in recent years linking air pollution to premature delivery, low birthweight and birth defects. For the first time, a new study performed by researchers at the University of [skipwords]Pennsylvania[/skipwords] showed that it could affect a woman's chances of conceiving in the first place.

According to the study, published in the journal Human Reproduction, living near a busy road cuts the chances of fertility treatment being successful by almost a quarter. Researchers studied thousands of IVF patients and found those who regularly breathed in traffic fumes were up to 24 percent less likely to conceive than those who lived in less polluted areas.

The researchers compared the success rates of almost 7,500 IVF patients with the levels of pollution near their homes and the clinics where they were being treated. They found consistent evidence that showed higher levels of nitrogen dioxide in the air was linked to lower odds of IVF success.  

One particular component, nitrogen dioxide, is the most likely cause. Nitrogen dioxide is a toxin pumped out by cars, trucks, power stations and gas grills. Researchers think it could have as big an impact on a woman's chances of having a baby as aging. Scientists don't know exactly how nitrogen dioxide causes harm, but it may be that fumes damage the eggs themselves or cut blood flow to the womb and placenta. And babies conceived via IVF are more vulnerable to damage than those conceived outside of a test-tube.