妊娠期PM2.5暴露影响胎儿生长的前瞻性队列研究

目的 探讨妊娠期PM_2.5及其组分暴露对胎儿生长的影响，并进一步识别暴露效应窗口。方法 选取江苏出生队列2016年1月至2019年10月招募的4 089对母子对，收集其基线信息、妊娠期诊疗信息、妊娠期PM_2.5及其组分暴露信息、妊娠满20周后的胎儿B超检查（头围、腹围、股骨长和估计体重）信息。利用广义线性混合模型进行暴露效应的估计，利用分布滞后非线性模型探讨暴露效应窗口。结果 妊娠期PM_2.5暴露浓度每升高10 μg/m³，胎儿头围、腹围和估计体重Z评分分别减小0.025（β=-0.025，95%CI：-0.048~-0.001）、0.026（β=-0.026，95%CI：-0.049~-0.003）和0.028（β=-0.028，95%CI：-0.052~-0.004），头围和估计体重生长受限风险分别增加8.5%（RR=1.085，95%CI：1.010~1.165）和13.5%（RR=1.135，95%CI：1.016~1.268）。PM_2.5组分中黑碳、有机物、硝酸盐、硫酸盐、铵盐暴露浓度升高均与头围Z评分减小显著相关，同时硫酸盐暴露的增加还与股骨长的Z评分减小有关。妊娠期PM_2.5暴露影响胎儿头围生长效应窗口为第2~5周，腹围为第4~13周以及第19~40周，股骨长为第4~13周以及第23~37周，估计体重为第4~12周以及第20~40周。结论 妊娠期PM_2.5及其组分暴露可能对胎儿生长产生不利影响，影响胎儿不同生长指标的效应窗口不完全一致。

Association between prenatal exposure to PM2.5 and fetal growth: a prospective cohort study

Objective　To investigate the association of exposure to PM_2.5 and its constituents during pregnancy and fetal growth and to further identify critical windows of exposure for fetal growth. Methods　We included 4 089 mother-child pairs from the Jiangsu Birth Cohort Study between January 2016 and October 2019. Data of general characteristics, clinical information, daily average PM_2.5 exposure, and its constituents during pregnancy were collected. Fetal growth parameters, including head circumference (HC), abdominal circumference (AC), and femur length (FL), were measured by ultrasound after 20 weeks of gestation, and then estimated fetal weight (EFW) was calculated. Generalized linear mixed models were adopted to examine the associations of prenatal exposure to PM_2.5andits constituents with fetal growth. Distributed lag nonlinear models were used to identify critical exposure windows for each outcome. Results　A 10 μg/m³ increase in PM_2.5 exposure during pregnancy was associated with a decrease of 0.025 (β=-0.025, 95%CI: -0.048- -0.001) in HC Z-score, 0.026 (β=-0.026, 95%CI: -0.049- -0.003) in AC Z-score, and 0.028 (β=-0.028, 95%CI:-0.052--0.004) in EFW Z-score, along with an increased risk of 8.5% (RR=1.085, 95%CI: 1.010-1.165) and 13.5% (RR=1.135, 95%CI: 1.016-1.268) for undergrowth of HC and EFW, respectively. Regarding PM_2.5 constituents, prenatal exposure to black carbon, organic matter, nitrate, sulfate (SO₄^2-) and ammonium consistently correlated with decreased HC Z-score. SO₄^2- exposure was also associated with decreased FL Z-scores. In addition, we found that gestational weeks 2-5 were critical windows for HC, weeks 4-13 and 19-40 for AC, weeks 4-13 and 23-37 for FL, and weeks 4-12 and 20-40 for EFW. Conclusions　Our findings demonstrated that exposure to PM_2.5 and its constituents during pregnancy could adversely affect fetal growth and the critical windows for different fetal growth parameters are not completely consistent.