Epidemiology, Human Genetics and Environmental Sciences, The University of Texas Health Science Center at Houston (UTHealth) School of Public Health, 1200 Pressler St., Houston, TX 77030, USA; Southwest Center for Occupational and Environmental Health (SWCOEH), UTHealth School of Public Health, 1200 Pressler St., Houston, TX 77030, USA.
Southwest Center for Occupational and Environmental Health (SWCOEH), UTHealth School of Public Health, 1200 Pressler St., Houston, TX 77030, USA; Epidemiology, Human Genetics and Environmental Sciences, UTHealth School of Public Health in San Antonio, 7411 John Smith Drive, Suite 1100, San Antonio, TX 78229, USA.
Environ Int. 2019 Oct;131:105067. doi: 10.1016/j.envint.2019.105067. Epub 2019 Jul 31.
Pregnant women may be vulnerable to changes in ambient temperature and warming climates. Recent evidence suggests that temperature increases are associated with placental abruption, a risk factor for stillbirth.
We investigated the effect of acute exposures to apparent temperature on stillbirths in Harris County, Texas, 2008-2013.
We conducted a case-crossover study to investigate the association between temperature and stillbirth among 708 women. We used data from the National Climatic Data Center to estimate maternal exposure to daily average apparent temperature over the days (lag days 1 through 6) preceding the stillbirth event. We employed symmetric bidirectional sampling to select six control periods one to three weeks before and after each event and applied conditional logistic regression to examine associations between increases of apparent temperature and stillbirths during the warm season (May-September). We adjusted for fine particulate matter (PM), nitrogen dioxide (NO) and ozone (O) and used stratified analysis to examine differences in risk by maternal race/ethnicity. We also examined the association among stillbirths with and without placental abruptions.
Independent of air pollutant exposures, a 10 °F increase in apparent temperature in the week preceding delivery (lag days 1 to 6) was positively associated with a 45% (adjusted OR = 1.45, 95% confidence interval (CI): 1.18, 1.77) increase in risk for stillbirth. Risks were elevated for stillbirths occurring in June through August, for Hispanic and non-Hispanic Black women, but not for non-Hispanic Whites. We also observed elevated risks associated with temperature increases in the few days preceding delivery among stillbirths caused by placental abruption, with the risk being highest on lag day 1 (OR = 1.93, 95% CI: 1.15, 3.23).
Independent of maternal ambient air pollutant exposure, we found evidence of an association between apparent temperature increases in the week preceding an event and risk of stillbirth. Risks for stillbirth varied by race/ethnicity. Further, in the first study to evaluate the impact of temperature on a specific complication during pregnancy, the risks were higher among mothers with placental abruption.
孕妇可能容易受到环境温度变化和气候变暖的影响。最近的证据表明，气温升高与胎盘早剥有关，胎盘早剥是死产的一个风险因素。
我们调查了 2008 年至 2013 年德克萨斯州哈里斯县明显温度的急性暴露对死产的影响。
我们进行了病例交叉研究，以调查 708 名妇女中温度与死产之间的关系。我们使用国家气候数据中心的数据来估计产妇在死产事件发生前几天（滞后 1 至 6 天）的日平均表观温度暴露。我们采用对称双向采样，在每个事件前后 1 至 3 周选择 6 个对照期，并应用条件逻辑回归来检查暖季（5 月至 9 月）中表观温度升高与死产之间的关联。我们调整了细颗粒物（PM）、二氧化氮（NO）和臭氧（O）的影响，并进行分层分析，以检查母体种族/族裔差异对风险的影响。我们还检查了胎盘早剥的死产与无胎盘早剥的死产之间的关联。
在不考虑空气污染物暴露的情况下，分娩前一周（滞后 1 至 6 天）明显温度升高 10°F，与死产风险增加 45%（调整后的比值比[OR] = 1.45，95%置信区间[CI]：1.18，1.77）相关。对于发生在 6 月至 8 月的死产、西班牙裔和非西班牙裔黑人妇女，风险升高，但对于非西班牙裔白人妇女则没有。我们还观察到与胎盘早剥相关的死产前几天的温度升高有关的风险升高，在滞后 1 天的风险最高（OR = 1.93，95%CI：1.15，3.23）。
在不考虑母体环境空气污染物暴露的情况下，我们发现事件前一周明显温度升高与死产风险之间存在关联的证据。死产风险因种族/族裔而异。此外，在第一项评估温度对妊娠特定并发症影响的研究中，胎盘早剥的母亲风险更高。
