Association of Seasonal Ambient Air Pollution With a Risk of Adverse Perinatal Outcomes in Full-term Pregnancies: A Retrospective Cohort Study in Wenzhou, China

Prenatal exposures to ambient air pollution have been proved to be associated with adverse perinatal outcomes in previous studies. However, few studies have examined the interaction between air pollution and season of conception on term low birth weight (TLBW) or macrosomia. Birth registry data of singleton live births in Wenzhou, China between January 2015 to December 2016 were accessed from the Wenzhou maternal and child health information management platform, and the ambient air pollutants in Wenzhou were obtained on the Chinese Air Quality Online Monitoring and Analysis Platform. Single/two-pollutant binary logistic regression models were used to assess the associations between ambient air pollutants (PM2.5, PM10, NO2, SO2, and O3) and TLBW/macrosomia, further exploring if the season of conception interacts with air pollution to impact birth weight. Finally, 213,959 term newborns were selected, including 2452 (1.1 %) TLBW infants and 13173 (6.1 %) macrosomia. In single/two-pollutant models, we observed an increased risk of TLBW associated with maternal exposure to PM2.5, PM10, SO2, and NO2 during the entire pregnancy, especially in the the 2nd trimester. Maternal exposure to O3 during the 1st trimester was associated with increased macrosomia risk, and O3 exposure during the 3rd trimester was associated with increased TLBW risk contrarily. Pregnant women conceived in the warm season may undergo more adverse ambient air environment that is related to the risks of TLBW.

Prenatal and postnatal exposure to ambient air pollution and asthma in neonatal jaundice infants

Background: Both air pollutants and neonatal jaundice (NJ) have known effects on childhood asthma, but higher total serum bilirubin (TSB) level was associated with lung protection. This study aimed to assess whether prenatal/postnatal exposure to air ambient pollutants is related to the inception of asthma in NJ infants. Material and methods: A nested case-control retrospective study of NJ infants was performed on the Kaohsiung Medical University Hospital Research Database between 2009 and 2019. The average concentration of particulate matter (PM2.5), sulfur dioxide (SO2), nitric dioxide (NO2) for six months, first and second years after the birth, and first, second and third trimesters prenatally were analyzed. The mild and significant NJ infants were categorized as TSB level < and ≧12 mg/dl, respectively. Asthma was defined as a diagnosis with medication. The adjusted odds ratio (aOR) and 95% confidence interval (CI) present the relationship between study periods and childhood asthma. Results: SO2 and NO2 exposure during prenatal periods were significantly associated with increased risk of childhood asthma in mild NJ infants (aOR (95% CI)), SO2: 1.20-1.34 (1.05-1.56); NO2: 1.06-1.07 (1.01-1.13)). Effects were more pronounced in postnatal exposure to three ambient air pollutants in mild jaundice infants. (aOR (95% CI), SO2: 1.33-1.41 (1.14-1.69); NO2: 1.07-1.31 (1.01-1.49; PM2.5:1.05 (1.00-1.10) Conclusion: Both SO2 and NO2 during prenatal and postnatal exposure in mild NJ infants were associated with childhood asthma. Whether taken phototherapy or not, significant NJ infants were spared by three ambient air pollutants.

Association Between Ambient Air Pollutants Exposure and Preterm Birth in Women Who Underwent in vitro Fertilization: A Retrospective Cohort Study From Hangzhou, China

Objectives: Exposure to air pollutants has been linked to preterm birth (PTB) after natural conception. However, few studies have explored the effects of air pollution on PTB in patients who underwent in vitro fertilization (IVF). We aimed to investigate the association between ambient air pollutants exposure and PTB risk in IVF patients.Methods: This retrospective cohort study included 2,195 infertile women who underwent IVF treatment from January 2017 and September 2020 in Hangzhou Women's Hospital. Totally 1,005 subjects who underwent a first fresh embryo(s) transfer cycle were analyzed in this study. Residential exposure to ambient six air pollutants (PM2.5, PM10, SO2, NO2, CO, O3) during various periods of the IVF timeline were estimated by satellite remote-sensing and ground measurement. Cox proportional hazards models for discrete time were used to explore the association between pollutants exposure and incident PTB, with adjustment for confounders. Stratified analyses were employed to explore the effect modifiers.Results: The clinical pregnancy and PTB rates were 61.2 and 9.3%, respectively. We found that PM2.5 exposure was significantly associated with an increased risk of PTB during 85 days before oocyte retrieval [period A, adjusted hazard ratio, HR=1.09, 95%CI: 1.02–1.21], gonadotropin start to oocyte retrieval [period B, 1.07 (1.01–1.19)], first trimester of pregnancy [period F, 1.06 (1.01–1.14)], and the entire IVF pregnancy [period I, 1.07 (1.01–1.14)], respectively. An interquartile range increment in PM10 during periods A and B was significantly associated with PTB at 1.15 (1.04–1.36), 1.12 (1.03–1.28), and 1.14 (1.01–1.32) for NO2 during period A. The stratified analysis showed that the associations were stronger for women aged &lt;35 years and those who underwent two embryos transferred.Conclusions: Our study suggests ambient PM2.5, PM10, and NO2 exposure were significantly associated with elevated PTB risk in IVF patients, especially at early stages of IVF cycle and during pregnancy.