School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
School of Public Health and Preventive Medicine, Monash University, Melbourne, Victoria, Australia.
Sci Total Environ. 2018 Sep 1;634:579-585. doi: 10.1016/j.scitotenv.2018.03.385. Epub 2018 Apr 7.
Pregnant women are susceptible to ambient temperature which may associate with adverse birth outcomes. These associations might change over time due to adaptation. However, no evidence is available worldwide.
To examine the effects of ambient temperature at three trimesters of pregnancy on preterm birth and stillbirth, and evaluate the effect changes during 1994-2013.
Information on birth outcomes and meteorological parameters during 1994-2013 were obtained in Brisbane, Australia. Cox proportional hazards models were employed to evaluate the effects of mean temperature during each trimester of pregnancy on preterm birth and stillbirth. An interaction term between time and temperature was used to assess the potential changes in effects of temperature over time.
Both low and high temperatures at the 3rd trimester of pregnancy significantly increased the risk of preterm birth, with similar hazard ratios (HRs) [95% confidence intervals (CIs)] for low [1.21 (1.16, 1.27)] and high [1.21 (1.16, 1.26)] temperatures in comparison with thresholds. Increased risk of stillbirth was significantly associated with both low and high temperatures at the 2nd trimester of pregnancy, and lower HRs were observed for low temperature [1.23 (1.04, 1.45)] than high temperature [1.47 (1.24, 1.74)], in comparison with thresholds. The effects of low temperature became stronger, whereas the effects of high temperature became weaker from 1994 to 2013 for both preterm birth and stillbirth.
Both low and high ambient temperatures during pregnancy increase the risks of preterm birth and stillbirth. Pregnant women should have adapted to high temperature but not low temperature.
孕妇易受环境温度影响，而环境温度可能与不良出生结局有关。这些关联可能会因适应而随时间发生变化。然而，目前全球范围内尚无相关证据。
本研究旨在探讨孕期三个阶段的环境温度对早产和死产的影响，并评估 1994 年至 2013 年期间这些影响的变化。
本研究在澳大利亚布里斯班收集了 1994 年至 2013 年期间的出生结局和气象参数信息。采用 Cox 比例风险模型评估孕期每个阶段的平均温度与早产和死产的关系。采用时间与温度的交互项来评估温度对时间的潜在影响变化。
孕期第 3 期的低温和高温均显著增加了早产的风险，与阈值相比，低温[1.21（1.16，1.27）]和高温[1.21（1.16，1.26）]的危险比（HRs）相似。第 2 期的低温和高温均与死产的风险显著相关，与阈值相比，低温的 HRs 较低[1.23（1.04，1.45）]，而高温的 HRs 较高[1.47（1.24，1.74）]。对于早产和死产，低温的影响从 1994 年到 2013 年逐渐增强，而高温的影响逐渐减弱。
孕期的低温和高温均会增加早产和死产的风险。孕妇可能已经适应了高温，但尚未适应低温。
