Research into early developmental periods has found that birth outcomes such as birth weight percentile and gestational age at birth are predictive of child development (Gutbrod et al., 2000). However, the research relating these birth outcomes with environmental factors such as maternal exposure to air pollutants remains relatively unexplored. Therefore, the current study examines whether exposure to air pollutants during pregnancy has an impact on birth weight percentile (BWP) and gestational age (GA) at birth. From a population of 272 mothers and children in the Denver area, no significant associations were found between child metrics and three types of pollutants (PM10, PM2.5, and O3), indicating that birth outcomes are not influenced by prenatal environmental exposures.