NEW YORK (May 16, 2012) – Although the entire duration of pregnancy is important for development, new research from the Columbia Center for Children’s Environmental Health suggests that exposure to polycyclic aromatic hydrocarbon (PAH) air pollutants during the first trimester has a greater impact on fetal growth than a similar level of exposure during the subsequent trimesters. The article “Fetal Window of Vulnerability to Airborne Polycyclic Aromatic Hydrocarbons on Proportional Intrauterine Growth Restriction”, was published in the online advance edition of the PLoS ONE Journal . This novel analysis was based in the Center’s ongoing birth cohort study in Krakow, Poland–a city with high levels of combustion-generated pollutants from coal burning. Paralleling the Center’s New York City cohort study, the Krakow cohort allows investigators to confirm and compare scientific findings internationally.
In a sample of healthy, non-smoking pregnant women living in Krakow, Poland with no known risks of adverse birth outcomes, personal exposure to eight airborne PAHs was monitored once during the second trimester for the entire cohort, and once each trimester within a subset.Repeated personal air monitoring was used to develop a model to estimate chronic PAH exposure during the entire gestational period for each individual newborn.
During the first trimester (as compared to the rest of pregnancy), each unit increase in PAH exposure was associated with a largest and most significant reductions in the fetal growth ratio, birth weight, and birth length. In addition, the same unit of exposure during the first trimester was also associated with the largest elevation in the head size to weight ratio of newborns. PAH exposure during the first trimester was associated with the greatest decrement of proportional fetal growth restriction.
First author, Dr. Hyunok Choi concludes, “the observations from the study support the need for reduction of air pollution from coal combustion for the protection of pregnant women and the embryo/fetus, particularly during the earliest stages of pregnancy.”
This study published online in the PLoS ONE Journal on April 24, 2012 and will be released in an upcoming print issue. The authors include Hyunok Choi,Lu Wang, Xihong Lin,John D. Spengler,and senior author Frederica P. Perera.