Vicedo-Cabrera Ana M, Olsson David, Forsberg Bertil
Department of Public Health and Clinical Medicine, Occupational and Environmental Medicine, Umeå University, SE901 87 Umeå, Sweden.
Int J Environ Res Public Health. 2015 Apr 10;12(4):3962-78. doi: 10.3390/ijerph120403962.
Recent evidence from studies performed mainly in warm climates suggests an association between exposure to extreme temperatures late in pregnancy and an increased risk of preterm delivery. However, there have been fewer studies on the effect of low temperatures. The aim of this study is to explore the potential association between both heat and cold during late pregnancy and an increased risk of preterm birth in the northern location of Stockholm, Sweden. All singleton spontaneous births that took place in greater Stockholm (1998-2006) were included. Non-linear and delayed effects of mean temperature on the risk of preterm birth were explored through distributed lag non-linear models. Extreme and moderate heat and cold were estimated separately through quasi-Poisson regression analysis in two seasonal periods (heat in warm season, cold in cold season). The risk of preterm birth increased by 4%-5% when the mean temperature reached the 75th percentile (moderate heat) four weeks earlier (reference: the annual median value), with a maximum cumulative risk ratio of 2.50 (95% confidence interval: 1.02-6.15). Inconsistent associations were obtained for cold and extreme heat. Exposure to moderately high temperatures during late pregnancy might be associated with an increase in risk of preterm birth in Stockholm.
近期主要在温暖气候地区开展的研究证据表明，孕期晚期暴露于极端温度与早产风险增加之间存在关联。然而，关于低温影响的研究较少。本研究的目的是探讨瑞典斯德哥尔摩北部地区孕期晚期的高温和低温与早产风险增加之间的潜在关联。纳入了在大斯德哥尔摩地区（1998 - 2006年）发生的所有单胎自然分娩。通过分布滞后非线性模型探讨平均温度对早产风险的非线性和延迟效应。在两个季节期间（温暖季节的高温、寒冷季节的低温），通过拟泊松回归分析分别估计极端和中度的高温和低温。当平均温度在四周前达到第75百分位数（中度高温）时（参考值：年度中位数），早产风险增加4% - 5%，最大累积风险比为2.50（95%置信区间：1.02 - 6.15）。对于低温和极端高温，获得的关联不一致。孕期晚期暴露于中度高温可能与斯德哥尔摩早产风险增加有关。
