Curtin School of Population Health, Curtin University, Perth, Kent Street, Bentley, Western Australia, 6102, Australia; Education, Culture, and Health Opportunities (ECHO) Ghana, ECHO Research Group International, Aflao, Ghana.
Curtin School of Population Health, Curtin University, Perth, Kent Street, Bentley, Western Australia, 6102, Australia; School of Public Health, University of Adelaide, Adelaide, South Australia, 5000, Australia.
Int J Hyg Environ Health. 2022 Aug;245:114029. doi: 10.1016/j.ijheh.2022.114029. Epub 2022 Aug 29.
Epidemiologic evidence on acute heat and cold stress and preterm birth (PTB) is inconsistent and based on ambient temperature rather than a thermophysiological index. The aim of this study was to use a spatiotemporal thermophysiological index (Universal Thermal Climate Index, UTCI) to investigate prenatal acute heat and cold stress exposures and spontaneous PTB. We conducted a space-time-stratified case-crossover analysis of 15,576 singleton live births with spontaneous PTB between January 1, 2000 and December 31, 2015 in Western Australia. The association between UTCI and spontaneous PTB was examined with distributed lag nonlinear models and conditional quasi-Poisson regression. Relative to the median UTCI, there was negligible evidence for associations at the lower range of exposures (1st to 25th percentiles). We found positive associations in the 95th and 99th percentiles, which increased with increasing days of heat stress in the first week of delivery. The relative risk (RR) and 95% confidence interval (CI) for the immediate (delivery day) and cumulative short-term (up to six preceding days) exposures to heat stress (99th percentile, 31.2 °C) relative to no thermal stress (median UTCI, 13.8 °C) were 1.01 (95% CI: 1.01, 1.02) and 1.05 (95% CI: 1.04, 1.06), respectively. Elevated effect estimates for heat stress were observed for the transition season, the year 2005-2009, male infants, women who smoked, unmarried, ≤ 19 years old, non-Caucasians, and high socioeconomic status. Effect estimates for cold stress (1st percentile, 0.7 °C) were highest in the transition season, during 2005-2009, and for married, non-Caucasian, and high socioeconomic status women. Acute heat stress was associated with an elevated risk of spontaneous PTB with sociodemographic vulnerability. Cold stress was associated with risk in a few vulnerable subgroups. Awareness and mitigation strategies such as hydration, reducing outdoor activities, affordable heating and cooling systems, and climate change governance may be beneficial. Further studies with the UTCI are required.
关于急性热应激和冷应激与早产 (PTB) 的流行病学证据不一致，并且基于环境温度而不是热生理指标。本研究旨在使用时空热生理指标（通用热气候指数，UTCI）来研究产前急性热应激和冷应激暴露与自发性 PTB 之间的关系。我们对 2000 年 1 月 1 日至 2015 年 12 月 31 日期间西澳大利亚州的 15576 例单胎活产自发性 PTB 进行了时空分层病例交叉分析。使用分布式滞后非线性模型和条件准泊松回归检验了 UTCI 与自发性 PTB 之间的关联。与中位数 UTCI 相比，在暴露的较低范围（第 1 至 25 百分位）几乎没有证据表明存在关联。我们发现，在分娩前第一周的热应激天数增加时，第 95 和 99 百分位的阳性关联增加。与无热应激（中位数 UTCI，13.8°C）相比，热应激（99 百分位，31.2°C）的即时（分娩日）和短期累积（前 6 天）暴露的相对风险（RR）和 95%置信区间（CI）分别为 1.01（95%CI：1.01，1.02）和 1.05（95%CI：1.04，1.06）。在过渡季节、2005-2009 年、男性婴儿、吸烟的女性、未婚、≤19 岁、非白种人以及高社会经济地位的女性中，热应激的升高效果估计值观察到升高。冷应激（第 1 百分位，0.7°C）的最高效应估计值出现在过渡季节、2005-2009 年以及已婚、非白种人和高社会经济地位的女性中。急性热应激与社会人口统计学脆弱性与自发性 PTB 风险升高有关。冷应激与少数脆弱亚组的风险相关。意识和缓解策略，例如补水、减少户外活动、负担得起的加热和冷却系统以及气候变化治理，可能是有益的。需要进一步使用 UTCI 进行研究。
