Advances in research on adverse birth outcomes associated with traffic-derived pollutants

In recent years, the relationship between traffic pollution and adverse birth outcomes has attracted increasing attention from scientists all over the world. A growing number of epidemiological studies have found that increased exposure to traffic-derived pollutants such as fine particulate matters, nitrogen oxides, ozone, and carbon monoxide are associated with higher risks of preterm birth, low birth weight, small for gestational age, and intrauterine growth retardation, but a few studies have not found such associations. The main reasons for the difference were biased exposure assessment and the lack of controlling confounders. This paper introduced exposure evaluation indexes and characteristics of particulate matters, nitrogen oxides, ozone, carbon monoxide, and traffic density and distance, and summarized their effects on preterm birth, low birth weight, small for gestational age, and intrauterine growth retardation, aiming to provide useful clues and innovative ideas for future research.