Duke Global Health Institute, Duke University, 310 Trent Drive, Durham, NC, 27710, USA.
Children's Environmental Health Initiative, University of Notre Dame, South Bend, IN, USA.
Environ Health. 2022 Jan 11;21(1):9. doi: 10.1186/s12940-021-00823-x.
Previous studies observed associations between prenatal exposure to fine particulate matter (≤ 2.5 μm; PM) and small-for-gestational-age (SGA) birth and lower birthweight percentile for gestational age. Few, if any, studies examine prenatal air pollution exposure and these pregnancy outcomes in neonates born to the same women. Here, we assess whether prenatal exposure to ambient fine particulate matter (PM) is associated with small-for-gestational-age (SGA) birth or birthweight percentile for gestational age in a longitudinal setting.
Detailed birth record data were used to identify women who had singleton live births at least twice in North Carolina during 2002-2006 (n = 53,414 women, n = 109,929 births). Prenatal PM exposures were calculated using daily concentration estimates obtained from the US EPA Fused Air Quality Surface using Downscaling data archive. Associations between PM exposure and birthweight percentile and odds of SGA birth were calculated using linear and generalized mixed models, comparing successive pregnancies to the same woman. Odds ratios and associations were also estimated in models that did not account for siblings born to the same mother.
Among NHW women, pregnancy-long PM exposure was associated with SGA (OR: 1.11 [1.06, 1.18]) and lower birthweight percentile (- 0.46 [- 0.74, - 0.17]). Trimester-specific PM was also associated with SGA and lower birthweight percentile. Among NHB women, statistically significant within-woman associations between PM, SGA, and birthweight percentile were not observed. However, in models that did not account for births to the same mother, statistically significant associations were observed between some PM exposure windows and higher odds of SGA and lower birthweight percentile among NHB women.
Findings suggest that a woman is at greater risk of delivering an SGA or low birthweight percentile neonate when she has been exposed to higher PM levels. The within-woman comparison implemented here better controls for factors that may differ between women and potentially confound the relationship between PM exposure and pregnancy outcomes. This adds to the evidence that PM exposure may be causally related to SGA and birthweight percentile, even at concentrations close to or below National Ambient Air Quality Standards.
先前的研究观察到产前暴露于细颗粒物（≤2.5μm；PM）与小胎龄儿（SGA）出生和出生时胎龄体重百分位较低之间存在关联。很少有研究（如果有的话）检查产前空气污染暴露与同一女性所生新生儿的这些妊娠结局之间的关系。在这里，我们评估在纵向环境中，产前暴露于环境细颗粒物（PM）是否与小胎龄儿（SGA）出生或出生时胎龄体重百分位有关。
详细的出生记录数据被用来识别 2002-2006 年期间在北卡罗来纳州至少两次单胎活产的女性（n=53414 名女性，n=109929 例分娩）。使用来自美国环保署融合空气质量表面的每日浓度估算值，通过向下缩放数据档案计算产前 PM 暴露量。使用线性和广义混合模型计算 PM 暴露量与体重百分位数和 SGA 出生几率之间的关联，将连续妊娠与同一女性进行比较。还在不考虑同一母亲所生兄弟姐妹的模型中估计了比值比和关联。
在 NHW 女性中，整个孕期的 PM 暴露与 SGA（比值比：1.11 [1.06，1.18]）和较低的出生体重百分位数（-0.46 [-0.74，-0.17]）有关。特定于妊娠的 PM 也与 SGA 和较低的出生体重百分位数有关。在 NHB 女性中，未观察到 PM、SGA 和出生体重百分位数之间存在统计学意义的个体内关联。然而，在不考虑同一母亲所生婴儿的模型中，在 NHB 女性中，一些 PM 暴露窗口与 SGA 和较低出生体重百分位数的几率较高之间存在统计学意义的关联。
研究结果表明，当女性暴露于较高水平的 PM 时，她更有可能分娩出 SGA 或低出生体重百分位数的新生儿。这里实施的个体内比较更好地控制了可能在女性之间存在差异并可能混淆 PM 暴露与妊娠结局之间关系的因素。这增加了证据表明，即使在接近或低于国家环境空气质量标准的浓度下，PM 暴露也可能与 SGA 和出生体重百分位数有因果关系。
