SYSTEMATIC REVIEW OF THE CURRENT EVIDENCES ABOUT THE IMPACT OF AMBIENT AIR POLLUTION ON BIRTH OUTCOMES.

Air pollution has been associated with several adverse effects on human health. Many large studies have demonstrated that increases in ambient air pollution result in increased morbidity and mortality in the general population.[1-3] In the last fifteen years, the possible link between exposure to air pollution and health effects has been intensively scrutinized, not only because of impacts to adults, but also because of a possible role in pregnancy outcomes. In fact, recent studies highlighted a possible relationship between high levels of air pollutants, such as particulate matter (PM), carbon monoxide (CO), nitrogen dioxide (NO2), and ozone (O3) and pregnancy outcomes such as low birth weight, prematurity and intrauterine growth retardation. Low birth weight and preterm birth are quite common in the general population (5 – 10 % of total live births) and are responsible for a large portion of perinatal morbidity and mortality in Western countries. Intrauterine growth retardation has been associated in several studies with an increased risk of developing chronic illnesses, such as diabetes, hypertension and cardiovascular diseases in adult life.[4-6] Four systematic reviews examining air pollution exposure and pregnancy outcomes were published between 2004 and 2005. The outcomes of interest were preterm delivery (PD) (defined as birth < 37 weeks), and intrauterine growth retardation or low birth weight (LBW) (defined as weight at birth &lt