The impact of prenatal exposure to a mixture of heavy metals on birth weight in newborns has been a topic of ongoing interest. In this study, 258 mothers and infants from the New Hampshire Birth Cohort Study (NHBCS) were selected as the study subjects, and the concentrations of seven heavy metals in the placenta, including Aluminum (Al), Cobalt (Co), Chromium (Cr), Nickel (Ni), Plumbum (Pb), Selenium (Se) and Arsenic (As) were collected. And the birth weight of newborns, the relevant covariates of mothers and newborns were collected. Three analytical methods, Weighted Quantile Sum (WQS) regression, Quantile g-computation (QGC) and Bayesian kernel machine regression (BKMR) were employed. After adjusting for maternal gestational age, pre-pregnancy BMI, smoking status, education level, parity, gestational age and newborn gender, the combined three methods showed that the total effect of mixed exposure of seven heavy metals on birth weight was negative. Specifically, the WQS analysis revealed that Se had the greatest impact on birth weight, followed by Al. The QGC results showed that the heavy metal associated with the reduction of birth weight was mainly Se and Al in female and male infants, respectively. The BKMR analysis demonstrated a negative combined effect of the seven heavy metals on birth weight in both male and female infants, with Se having the highest posterior inclusion probabilities (PIPs) for female infants (0.45), and Al having the highest PIPs for male infants (0.64) after stratification by gender. In summary, mixed exposure to heavy metals during pregnancy was associated with a decrease in newborn birth weight. Furthermore, there are gender effects with Se and Al associated with decreased birth weight in female and male infants, respectively. These findings provide a theoretical basis for the development of public health policies aimed at preventing adverse pregnancy outcomes and improving the health of newborns.
妊娠期重金属混合暴露对新生儿出生体重的影响一直备受关注。本研究选取美国新罕布什尔州出生队列研究（NHBCS）中258对母婴作为研究对象，采集了胎盘中铝（Al）、钴（Co）、铬（Cr）、镍（Ni）、铅（Pb）、硒（Se）、砷（As）等七种重金属的浓度，同时收集新生儿出生体重及母亲和新生儿的相关协变量信息。采用加权分位数和回归（WQS）、分位数g计算（QGC）和贝叶斯核机器回归（BKMR）三种方法进行分析。调整了母亲孕龄、孕前BMI、吸烟状况、受教育程度、产次、胎龄及新生儿性别后，综合三种方法表明七种重金属混合暴露对出生体重的总效应呈负向关系。具体来看，WQS结果显示，Se对出生体重的效应最大，其次为Al；QGC结果显示，与女婴出生体重降低相关的重金属主要是Se，与男婴出生体重降低相关的主要是Al；BKMR结果显示，胎盘7种重金属混合暴露对男婴和女婴的出生体重都有负联合效应，按性别分层后，女婴中后验包含概率（PIP）最高的是Se（0.45），男婴中PIP最高是Al（0.64）。综上表明，妊娠期重金属混合暴露与新生儿出生体重降低相关，且存在性别差异，Se和Al分别与女婴和男婴的出生体重降低相关联。这一发现为预防不良妊娠结局和制定改善新生儿健康状况的卫生政策提供了理论依据。.