PM10 air pollution exposure during pregnancy and term low birth weight in Allegheny County, PA, 1994-2000

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).

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.

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.

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.