Jiajia Wang1,2, Shilu Tong2, Gail Williams3, Xiaochuan Pan4. 1. From the School of Public Health and Beijing Key Laboratory of Environmental Toxicology, Capital Medical University, Beijing, China. 2. School of Public Health and Social Work, Institute of Health and Biomedical Innovation, Queensland University of Technology, Brisbane, Australia. 3. School of Public Health, University of Queensland, Brisbane, Australia. 4. School of Public Health, Peking University, Beijing, China.
Abstract
BACKGROUND: Several studies have investigated the acute effects of high ambient temperature or extreme weather on preterm birth and stillbirth. However, little was known about whether there are any particular stages during which high ambient temperature or heat wave exposure is most harmful to fetal growth. The aim of this study was to examine the effects of heat wave exposure in different gestational months on the risk of preterm birth and stillbirth. METHODS: Based on all singleton birth records between 2000 and 2010 and the corresponding environmental data in Brisbane, Australia, we explored relationships between heat wave exposure in different months of pregnancy and preterm birth or stillbirth. Six heat wave definitions were used in this study. After controlling for confounding factors, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using extended Cox proportional hazards regression models with time-dependent covariates. RESULTS: For most heat wave definitions, the adjusted HRs of preterm birth varied by different gestational months and ranged from 1.08 (HR = 1.08; 95% CI = 1.00, 1.18) to 1.53 (HR = 1.53; 95% CI = 1.41, 1.68). Heat wave exposure in early pregnancy was more likely to increase the risk of stillbirth compared with heat wave exposure in late pregnancy. CONCLUSIONS: Overall, we found relationships between preterm birth and heat wave exposure in all months of pregnancy based on most heat wave definitions. We did not find a specifically high period of susceptibility during pregnancy for preterm birth associated with heat wave exposure. However, earlier gestational months might be key exposure windows for heat-wave-affected stillbirth.
BACKGROUND: Several studies have investigated the acute effects of high ambient temperature or extreme weather on preterm birth and stillbirth. However, little was known about whether there are any particular stages during which high ambient temperature or heat wave exposure is most harmful to fetal growth. The aim of this study was to examine the effects of heat wave exposure in different gestational months on the risk of preterm birth and stillbirth. METHODS: Based on all singleton birth records between 2000 and 2010 and the corresponding environmental data in Brisbane, Australia, we explored relationships between heat wave exposure in different months of pregnancy and preterm birth or stillbirth. Six heat wave definitions were used in this study. After controlling for confounding factors, hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated using extended Cox proportional hazards regression models with time-dependent covariates. RESULTS: For most heat wave definitions, the adjusted HRs of preterm birth varied by different gestational months and ranged from 1.08 (HR = 1.08; 95% CI = 1.00, 1.18) to 1.53 (HR = 1.53; 95% CI = 1.41, 1.68). Heat wave exposure in early pregnancy was more likely to increase the risk of stillbirth compared with heat wave exposure in late pregnancy. CONCLUSIONS: Overall, we found relationships between preterm birth and heat wave exposure in all months of pregnancy based on most heat wave definitions. We did not find a specifically high period of susceptibility during pregnancy for preterm birth associated with heat wave exposure. However, earlier gestational months might be key exposure windows for heat-wave-affected stillbirth.
Authors: Yohani Dalugoda; Jyothi Kuppa; Hai Phung; Shannon Rutherford; Dung Phung Journal: Int J Environ Res Public Health Date: 2022-02-04 Impact factor: 3.390
Authors: Agalyaa Puhenthirar; James W Smallcombe; William Casasola; Daniela S Inoue; Georgia K Chaseling; Nicholas Ravanelli; Kate M Edwards; Ollie Jay Journal: Sports Med Date: 2021-06-24 Impact factor: 11.136