Clemens Tom, Turner Steve, Dibben Chris
School of Geosciences, University of Edinburgh, Edinburgh, Scotland, UK.
Child Health, University of Aberdeen, Aberdeen, Scotland, UK.
Environ Int. 2017 Oct;107:216-226. doi: 10.1016/j.envint.2017.07.018. Epub 2017 Jul 25.
Maternal ambient air pollution exposure is associated with reduced birthweight. Few studies have examined the effect on growth in utero and none have examined the effect of exposure to particulates less than 2.5µm (PM) and possible effect modification by smoking status.
Examine the effect of maternal exposure to ambient concentrations of PM, PM and nitrogen dioxide (NO) for in utero fetal growth, size at birth and effect modification by smoking status.
Administratively acquired second and third trimester fetal measurements (bi-parietal diameter, femur length and abdominal circumference), birth outcomes (weight, crown heel length and occipito-frontal circumference) and maternal details were obtained from routine fetal ultrasound scans and maternity records (period 1994-2009). These were modelled against residential annual pollution concentrations (calendar year mean) adjusting for covariates and stratifying by smoking status.
In the whole sample (n=13,775 pregnancies), exposure to PM, PM and NO was associated with reductions in measurements at birth and biparietal diameter from late second trimester onwards. Among mothers who did not smoke at all during pregnancy (n=11,075), associations between biparietal diameter and pollution exposure remained significant but were insignificant among those who did smoke (n=2700). Femur length and abdominal circumference were not significantly associated with pollution exposure.
Fetal growth is strongly associated with particulates exposure from later in second trimester onwards but the effect appears to be subsumed by smoking. Typical ambient exposures in this study were relatively low compared to other studies and given these results, it may be necessary to consider reducing recommended "safe" ambient air exposures.
母亲暴露于环境空气污染中与出生体重降低有关。很少有研究考察其对子宫内生长的影响，且尚无研究考察暴露于小于2.5微米的颗粒物（PM）的影响以及吸烟状况可能产生的效应修正作用。
考察母亲暴露于环境浓度的PM、PM和二氧化氮（NO）对子宫内胎儿生长、出生时大小的影响以及吸烟状况的效应修正作用。
从常规胎儿超声扫描和产科记录（1994 - 2009年期间）中获取通过行政手段获得的孕中期和孕晚期胎儿测量数据（双顶径、股骨长度和腹围）、出生结局（体重、顶臀长度和枕额周长）以及母亲的详细信息。将这些数据与居住地年度污染浓度（日历年平均值）进行建模，对协变量进行调整，并按吸烟状况分层。
在整个样本（n = 13775例妊娠）中，暴露于PM、PM和NO与出生时测量值以及从孕中期晚期开始的双顶径减小有关。在孕期完全不吸烟的母亲（n = 11075）中，双顶径与污染暴露之间的关联仍然显著，但在吸烟的母亲（n = 2700）中不显著。股骨长度和腹围与污染暴露无显著关联。
从孕中期晚期开始，胎儿生长与颗粒物暴露密切相关，但这种效应似乎被吸烟所掩盖。与其他研究相比，本研究中的典型环境暴露相对较低，鉴于这些结果，可能有必要考虑降低推荐的“安全”环境空气暴露水平。
