Introduction The purpose of this study was to examine the secular trends in the rates of stillbirth by race and ethnicity and to examine the risk of stillbirth with increase in ambient air pollution in each of the three trimesters of pregnancy and with short term increase in ambient air pollution. Materials and Methods We used New Jersey births and fetal deaths records linked to hospital discharge data for 1997-2005. Gestational age specific stillbirth rates were calculated by fetus at risk approach and Cox proportional hazard model was used to estimate the risk of stillbirth. We used logistic regression models to estimate the risk of stillbirth associated with incremental increase in ambient air pollution in each of the three trimesters. The association of transient increase in ambient air pollution with the risk of stillbirth was analyzed with a time stratified case crossover design using conditional logistic regression. Results The rate of stillbirth was 4.4 per 1000 total births (3.4 for white non-Hispanics, 7.9 for black non-Hispanics and 4.4 for Hispanics /1000 total births) in NJ for the period 1997 to 2005. The rates of stillbirth decreased only for white non-Hispanics but remained unchanged for other race/ethnicity groups. In the first trimester, increased risk of stillbirth was associated with interquartile range increase in PM2.5 (OR 1.14, 95% CI, 1.00, 1.31) and NO2 (OR 1.10, 95% CI, 1.00, 1.21) and SO2 (OR 1.12, 95% CI, 1.00, 1.25) and with PM2.5 ( OR 1.20, 95% CI, 1.04, 1.37) in the second trimester and with SO2 in both 2nd trimester (OR 1.21, 95% CI, 1.03, 1.29) and the 3rd trimester (OR 1.18, 95% CI, 1.00, 1.28). There was an increased risk of stillbirth for each interquartile range increase in 2nd day concentration of SO2 (RR 1.12, 95% CI, 1.02-1.23) and CO (RR 1.20, 95% CI, 1.04-1.38). Conclusion We found an increased risk of stillbirth associated with increase in ambient air pollution in all three trimesters of pregnancy and with short term increase in ambient air pollution. Understanding the biological mechanism for the association of criteria pollutants with the risk of stillbirth merits attention.Ph.D.Includes bibliographical referencesIncludes vitaby Ambarina S. Fai
