Does Exposure to Ambient Air Pollution Affect Gestational Age and Newborn Weight?-A Systematic Review

Abstract

Current evidence suggests that airborne pollutants have a detrimental effect on fetal growth through the emergence of small for gestational age (SGA) or term low birth weight (TLBW). The study's objective was to critically evaluate the available literature on the association between environmental pollution and the incidence of SGA or TLBW occurrence. A comprehensive literature search was conducted across Pubmed/MEDLINE, Web of Science, Cochrane Library, EMBASE, and Google Scholar using predefined inclusion and exclusion criteria. The methodology adhered to the PRISMA guidelines. The systematic review protocol was registered in PROSPERO with ID number: CRD42022329624. As a result, 69 selected papers described the influence of environmental pollutants on SGA and TLBW occurrence with an Odds Ratios (ORs) of 1.138 for particulate matter ≤ 10 μm (PM₁₀), 1.338 for particulate matter ≤ 2.5 μm (PM_2.5), 1.173 for ozone (O₃), 1.287 for sulfur dioxide (SO₂), and 1.226 for carbon monoxide (CO). All eight studies analyzed validated that exposure to volatile organic compounds (VOCs) is a risk factor for SGA or TLBW. Pregnant women in the high-risk group of SGA occurrence, i.e., those living in urban areas or close to sources of pollution, are at an increased risk of complications. Understanding the exact exposure time of pregnant women could help improve prenatal care and timely intervention for fetuses with SGA. Nevertheless, the pervasive air pollution underscored in our findings suggests a pressing need for adaptive measures in everyday life to mitigate worldwide environmental pollution.

Keywords: ambient air pollution; carbon monoxide (CO); nitrogen dioxide (NO2); ozone (O3); particulate matter ≤ 10 μm (PM10); particulate matter ≤ 2.5 μm (PM2.5); small for gestational age (SGA); sulfur dioxide (SO2); term low birth weight (TLBW).

Figure 1

PRISMA systematic review flow diagram.