Purpose: Low birth weight has been associated with increased risks of mortality and/or morbidity in childhood and adulthood. Epidemiological studies suggest that maternal exposure to air pollution, especially particulate matter during pregnancy, is associated with an increased risk of delivering a low birth weight infant. The aim of this study is to explore the association between exposure to particulate matter (PM10) during pregnancy and term low birth weight (LBW: birth weight <2,500 g and gestation age ≥ 37 weeks).
Methods: Birth data from the Allegheny County Health Department, Pittsburgh, PA, USA and PM10 air data generated with inverse-distance interpolation by RAND's Center for Population Health and Health Disparities, were obtained. The study population consisted of all term singleton live births (gestational age ≥ 37 weeks) born between January 1, 1994 to December 31, 2000. Infants with birth weight <2,500 g were classified as LBW. Logistic regression with robust variance estimation was performed to estimate the odds ratios of LBW per inter-quartile range increase in PM10.
Results: The results showed that the odds ratios of term LBW per inter-quartile range increase in PM10 were 1.13 (95% CI: 1.02-1.25) during the first trimester and 1.10 (95% CI: 1.00-1.22) during the second trimester after adjustment for other important covariates, respectively.
Conclusion: The findings of the study support the hypothesis that exposure to PM10 is associated with increased levels of term LBW. Further studies are warranted to corroborate these findings.