Document Type : original article
Authors
1 1 Metabolic Liver Diseases Research Center, Isfahan University of Medical Sciences, Isfahan, Iran
2 Endocrine and Metabolism Research Center, Isfahan University of Medical Sciences, Isfahan, IRAN
3 Pediatrics Department, Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-communicable Disease, Emam Hossein Children’s Hospital, Isfahan University of Medical Sciences, Isfahan, Iran
4 2 Child Growth and Development Research Center, Research Institute for Primordial Prevention of Non-Communicable Disease, Isfahan University of Medical Sciences, Isfahan, Iran
Abstract
Background: Air pollution as a major health concern in the world can adversely affect pregnant women and their newborns' thyroid function. We evaluated the association between prenatal exposure to air pollutants and cord-blood thyroid hormone levels.
Method: This cross-sectional study was conducted as a sub-study of the PERSIAN birth cohort on mothers and their newborns from October 2019 to September 2021. All participants, related data, and cord blood samples were obtained from the Isfahan center of this study. The air quality index (AQI) extracted from its official website was used to assess overall air quality during pregnancy. The association between mean levels of AQI in the three trimesters with cord blood thyroid hormone levels was evaluated.
Results: In 195 mothers with a mean age of 29.79(5.46), the mean of TSH and free T4 was 6.96 IU/L and 1ng/dl, respectively. The total days with moderate AQI (51-100) were higher than other AQI categories over the three trimesters. This study found no significant association between the mean cord-blood TSH and AQI>100, (P>0.05). The mean cord-blood FT4 had a negative association with total unhealthy days for sensitive groups in the first trimester and total very unhealthy days in the third trimester. The mean cord-blood FT4 was positively associated with unhealthy days in the second trimester.
Conclusion: The cord-blood FT4 levels associated with prenatal exposure to AQI higher than 100. These results highlight the need for air pollution management to minimize neonatal thyroid hormone alteration and its critical sequelae.
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