Prenatal Exposure to Air Pollution May Affect Newborn’s Thyroid Function Interview with:

Carrie Breton ScD Associate Professor and Director of the MADRES Center  Division of Environmental Health Los Angeles, CA 90032

Dr. Breton

Carrie Breton ScD
Associate Professor and Director of the MADRES Center
Division of Environmental Health
Los Angeles, CA 90032 What is the background for this study? What are the main findings?

Response: I am interested in how the environment can influence our very early development, starting in the womb. I have studied the health effects of air pollutants on children for several years and wanted to focus now on the earliest windows of susceptibility.  Thyroid hormones play a critical role in fetal growth and development. We knew we could get information on newborn thyroid levels from the California Department of Public Health’s newborn screening program therefore look at this question in our study population.

We found that exposure to high levels of PM2.5 and PM10 throughout most of pregnancy affected TT4 levels in newborns. What should readers take away from your report?

Response: We found that exposure to high levels of air pollution in pregnancy may have subtle influences on the developing fetal thyroid gland and its subsequent function.

Most clinical concerns have focused on thyroid hormone deficiencies in pregnancy which have been associated with various adverse effects including reduced fetal growth and neurodevelopment. However, thyroid hormones are tightly regulated and there may be an optimal range above which high levels may also be detrimental. What recommendations do you have for future research as a result of this work?

Response: Further research should evaluate the many indicators of thyroid function simultaneously, and distinguish between the free and bound T4. Evaluating maternal thyroid levels, in conjunction with infant levels, would help our understanding of which are truly the most affected by pollution.

I have no financial conflicts to disclose. 


Howe CG, Eckel SP, Habre R, et al. Association of Prenatal Exposure to Ambient and Traffic-Related Air Pollution With Newborn Thyroid FunctionFindings From the Children’s Health StudyJAMA Network Open.2018;1(5):e182172. doi:10.1001/jamanetworkopen.2018.2172

Sep 17, 2018 @ 3:00 pm


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