A mix of air pollutants in early pregnancy linked to risk of premature birthExposure to a combination of common air pollutants during early pregnancy could significantly increase the risk of premature birth, according to new research that suggests current air quality measures may underestimate the dangers to expectant mothers. The study used machine learning to identify patterns in air pollution exposure across Utah between 2013 and 2016. Babies born this early are at greater risk of serious health complications, making early preterm birth a major public health concern. Previous studies have linked individual pollutants, such as PM2.5 or ozone, to premature birth. They then examined how exposure to these mixtures during each week of pregnancy affected the risk of early preterm birth.