A Review on the Relationship between Maternal Exposure to Ambient Air Particulate Matter (PM10) and Infants’ Birth Weight in Asia

Abstract

Low birth weight occurs in one in four livebirths in Southeast Asian region. It is contributed by multiple factors including the maternal exposures to the elements in the environment during the antenatal period. Particulate matter (PM₁₀) pollution in Southeast Asian region has been extensively studied with known attributions and sources. It is also known that PM₁₀is able to restrict foetal grow that molecular level. This review intended to investigate whether the unborn in Asia are affected by the air pollutants indirectly through their mothers. Publications from Scopus and Science Direct digital databases in Asian region from 2015 onwards were reviewed. Details collected were the year of publication and study location, the study design, investigated air pollutants, exposure estimation methods used the timing of exposure in relation to pregnancy, pregnancy outcome measured and the relative risk or odds of effect. A total of eight full text articles were included. Most of the studies were of cohort and quasi experimental designs, involving local air monitoring measurements to assign exposure. There were more studies considered multiple air pollutants as contributing risk rather than a single pollutant. The exposure was measured according to stages of pregnancy and the trimester stratification is the most often method used. Modalities used in representing birth outcomes were not confined to birth weight alone but also included the length of gestation. Exposure to PM₁₀ have been found to be associated with reduction in birth weight and increased risk for preterm birth in Asia.