Maternal exposure to PM2.5 may increase the risk of congenital hypothyroidism in the offspring: a national database based study in China

Abstract

BackgroundMaternal exposure to air pollution is related to fetal dysplasia. However, the association between maternal exposure to air pollution and the risk of congenital hypothyroidism (CH) in the offspring is largely unknown.MethodsWe conducted a national database based study in China to explore the association between these two parameters. The incidence of CH was collected from October 1, 2014 to October 1, 2015 from the Chinese Maternal and Child Health Surveillance Network. Considering that total period of pregnancy and consequently the total period of particle exposure is approximately 10 months, average exposure levels of PM2.5, PM10 and Air Quality Index (AQI) were collected from January 1, 2014 to January 1, 2015. Generalized additive model was used to evaluate the association between air pollution and the incidence of CH, and constructing receiver operating characteristic (ROC) curve was used to calculate the cut-off value.ResultsThe overall incidence of CH was 4.31 per 10,000 screened newborns in China from October 1, 2014 to October 1, 2015. For every increase of 1 μg/m3 in the PM2.5 exposure during gestation could increase the risk of CH (adjusted OR = 1.016 per 1 μg/m3 change, 95% CI, 1.001–1.031). But no significant associations were found with regard to PM10 (adjusted OR = 1.009, 95% CI, 0.996–1.018) or AQI (adjusted OR = 1.012, 95% CI,0.998–1.026) and the risk of CH in the offspring. The cut-off value of prenatal PM2.5 exposure for predicting the risk of CH in the offspring was 61.165 μg/m3.ConclusionsThe present study suggested that maternal exposure to PM2.5 may exhibit a positive association with increased risk of CH in the offspring. We also proposed a cut-off value of PM2.5 exposure that might determine reduction in the risk of CH in the offspring in highly polluted areas.

Impact of air pollution exposure during various periods of pregnancy on term birth weight: a large-sample, retrospective population-based cohort study

“…The average exposure values of AQI, PM 2.5 , PM 10 , SO 2 , NO 2 CO, and O 3 from 2015 to 2018 in Xi’an city were estimated based on hourly average exposure levels by the weighted average method. Generalized additive model (GAM) fitting in the Gaussian distribution was performed to evaluate the nonlinear relationship of air pollution exposure and birth weight (Shang et al 2019 ). After fitting the related confounders, including maternal age, gestational age ethnicity, and pregnancy season, the degrees of freedom of confounders were calculated by using the Akaike information criterion (AIC).…”

“…As the most sensitive populations, pregnant women and newborns are more vulnerable to the adverse effects of ambient air pollution. Some epidemiological studies indicated that maternal exposure to air pollution had adverse effects on infant health, such as adverse birth outcome and respiratory and neurodevelopmental effects (Backes et al 2013 ; Forns et al 2018 ; Korten et al 2017 ; Pedersen et al 2017 ; Shang et al 2019 ; Yorifuji et al 2015 ). Among them, birth weight is one of the most important predictors of morbidity and mortality in neonates and childhood and adult morbidity.…”

Maternal exposure to O3 and NO2 may increase the risk of newborn congenital hypothyroidism: a national data-based analysis in China

“…Disease and economic afford from adverse pregnancy outcomes caused by air pollution was enormous which should be valued. Until now, researches on air pollution during pregnancy were mainly focused on maternal complications, fetal development, and congenital malformation; limited studies paid attention to metabolic diseases such as newborn congenital hypothyroidism (CH) (Li et al 2019 ).…”

Associations between ambient air pollution and daily incidence of pediatric hand, foot and mouth disease in Ningbo, 2014–2016: a distributed lag nonlinear model

“…This corresponds to almost one in eight deaths globally (http://www.who.int/phe/health_ topics/outdoorair/databases/FINAL_HAP_AAP_BoD_24March2014.pdf?ua=1). Epidemiological and clinical studies have demonstrated that exposure to air pollution, and particulate matter (PM 10 and PM 2.5 ) in particular, is associated with childhood diseases such as allergy, asthma and congenital hypothyroidism and increases the risks once a disease has been contracted [13][14][15]. These findings suggest that essential air pollution sources, such as nitrogen dioxide (NO 2 ), ozone (O 3 ) and sulphur dioxide (SO 2 ) could also contribute to HDMF outbreaks.…”