Contreras Zuelma A, Heck Julia E, Lee Pei-Chen, Cui Xin, Hobel Calvin J, Janzen Carla, Lurmann Fred, Ritz Beate
Department of Epidemiology, Fielding School of Public Health, University of California, Los Angeles, CA, USA.
Department of Health Care Management, College of Health Technology, National Taipei University of Nursing and Health Sciences, Taipei, Taiwan.
Environ Epidemiol. 2018 Sep;2(3):e017. doi: 10.1097/EE9.0000000000000017. Epub 2018 Jun 21.
Prenatal exposure to air pollution and smoking increases the risk of pregnancy complications and adverse birth outcomes, but pathophysiologic mechanisms are still debated. Few studies to date have examined the influence of air pollution on uterine vascular resistance and no studies have examined the independent impact of these exposures. We aimed to assess the impact of prenatal exposure to traffic-related air pollution and smoking on uterine vascular resistance.
Our study included 566 pregnant women recruited between 1993 and 1996 in Los Angeles who completed visits at three gestational ages. Information on smoking was collected and uterine vascular resistance was measured at each visit by Doppler ultrasound. We calculated three resistance indices: the resistance index (RI), the pulsatility index (PI), and the systolic/diastolic (S/D) ratio. We estimated exposure to NO at the home address of the mother using a land use regression (LUR) model and to NO using CALINE4 air dispersion modeling. We used generalized linear mixed models to estimate the effects of air pollution and smoking on uterine vascular resistance indices.
LUR-derived NO and CALINE4-derived NO exposure increased the risk of high uterine artery resistance in late pregnancy. Smoking during pregnancy also increased the risk of higher uterine resistance and contributed to bilateral notching in mid-pregnancy.
Our results suggest that uterine vascular resistance is a mechanism underlying the association between smoking and air pollution, and adverse birth outcomes.
孕期暴露于空气污染和吸烟会增加妊娠并发症及不良分娩结局的风险，但病理生理机制仍存在争议。迄今为止，很少有研究探讨空气污染对子宫血管阻力的影响，也没有研究考察这些暴露因素的独立影响。我们旨在评估孕期暴露于交通相关空气污染和吸烟对子宫血管阻力的影响。
我们的研究纳入了1993年至1996年在洛杉矶招募的566名孕妇，她们在三个孕周完成了访视。收集吸烟信息，并在每次访视时通过多普勒超声测量子宫血管阻力。我们计算了三个阻力指数：阻力指数（RI）、搏动指数（PI）和收缩/舒张（S/D）比值。我们使用土地利用回归（LUR）模型估计母亲家庭住址处的一氧化氮（NO）暴露，并使用CALINE4空气扩散模型估计NO暴露。我们使用广义线性混合模型来估计空气污染和吸烟对子宫血管阻力指数的影响。
LUR模型得出的NO暴露和CALINE4模型得出的NO暴露增加了妊娠晚期子宫动脉阻力高的风险。孕期吸烟也增加了子宫阻力升高的风险，并导致妊娠中期双侧切迹。
我们的结果表明，子宫血管阻力是吸烟与空气污染及不良分娩结局之间关联的潜在机制。
