目的·分析出生前母体重（类）金属复合暴露与子代认知和气质发育的相关性。方法·利用2010—2012年在上海开展的前瞻性出生队列，在妊娠28~36周采集孕妇静脉血，检测静脉血重（类）金属浓度。在幼儿24~36月龄时，使用格塞尔发育量表和幼儿气质量表分别评估幼儿的认知和气质发育。通过问卷及医院病历系统收集孕妇及幼儿的基本信息。使用贝叶斯核机器回归（Bayesian kernel machine regression，BKMR）模型评估出生前母体重（类）金属复合暴露对幼儿认知和气质发育的影响。结果·最终共纳入139对信息完整的母婴。入组时孕妇年龄为（29.39±3.41）岁，婴儿出生体质量为（3.47±0.42）kg，女性占59.71%，随访时幼儿月龄为（32.91±2.69）个月。根据以往研究证据和多元线性回归模型筛选出和幼儿认知和气质发展可能有关联的4种重（类）金属元素，分别为铬（Cr）、锰（Mn）、砷（As）和铅（Pb）。出生前母体静脉血Mn、Pb、As、Cr的浓度中位数分别为3.32、3.60、2.03、1.78 μg/dL。BKMR模型分析发现，矫正相关混杂因素后，当4种重（类）金属的整体浓度高于第50个百分位时，随着重（类）金属整体浓度的增加，幼儿的精细动作发育商呈下降趋势，且幼儿气质量表的适应性、坚持性和反应阈维度得分均呈下降趋势。其中出生前母体Mn暴露对幼儿精细动作发育影响的贡献最大［后验包含概率（posterior inclusion probabilities，PIP）=0.617］，As暴露对幼儿坚持性维度影响的贡献最大（PIP=0.656），Cr暴露对幼儿反应阈维度影响的贡献最大（PIP=0.447），4种重（类）金属暴露对幼儿适应性维度影响的贡献相近。结论·出生前母体重（类）金属（Mn、As、Pb、Cr）复合暴露与幼儿的精细动作发育和气质的适应性、坚持性和反应阈维度发育之间可能存在相关性；尤其要重视Mn暴露与幼儿精细动作发育之间，以及As和Cr暴露与幼儿气质发育之间的关系。

Objective ·To analyze the relationship between prenatal mixed heavy metal/metalloid exposure and the cognitive and temperament development of the offspring. Methods ·A prospective birth cohort study was conducted in Shanghai from 2010 to 2012. Maternal venous blood samples were collected at 28?36 weeks of gestation to measure prenatal maternal blood heavy metal/metalloid concentrations. At 24?36 months of age, the cognitive and temperament development of the offspring were assessed by using Gesell Developmental Scale and Toddler Temperament Scale, respectively. Demographic and clinical information of mothers and children was collected via questionnaires and hospital medical records. Bayesian kernel machine regression (BKMR) models were employed to assess the effects of prenatal mixed heavy metal/metalloid exposure on toddlers' cognitive and temperament development. Results ·A total of 139 mother-child pairs with complete data were included in the study. At enrollment, the mean maternal age was (29.39±3.41) years, and the mean birth weight of the infants was (3.47±0.42) kg, with 59.71% female infants. At follow-up, the average age of the toddlers was (32.91±2.69) months. Based on prior research and multivariable linear regression models, four heavy metals/metalloid—chromium (Cr), manganese (Mn), arsenic (As), and lead (Pb)—were identified as potentially associated with cognitive and temperament development in children. The median concentrations of Mn, Pb, As, and Cr in the maternal venous blood during pregnancy were 3.32, 3.60, 2.03, and 1.78 μg/dL, respectively. After adjusting for related confounders, the BKMR analyses found that when the overall concentrations of the four heavy metals/metalloid (Cr, Mn, As, and Pb) were higher than the 50th percentile, children's fine motor development quotients showed a decreasing trend as the overall concentrations of the four heavy metals/metalloid increased. Scores for adaptability, persistence, and threshold of response on the temperament scale showed a decreasing trend as well. Prenatal Mn exposure levels made the greatest contribution to the effects on children's fine motor development [PIP (posterior inclusion probability)=0.617], prenatal As exposure levels made the greatest contribution to the effects on children's persistence trait (PIP=0.656), and prenatal Cr exposure levels made the greatest contribution to the effects on children's reaction threshold trait (PIP=0.447). The contribution of all four heavy metals/metalloid to the effects on children's adaptive dimension was similar. Conclusion ·Children's fine motor development and the adaptability, persistence, and threshold traits of temperament may be related to prenatal mixed exposure to heavy metals/metalloid (Mn, As, Pb, and Cr). Particular attention should be paid to the relationship between prenatal Mn exposure and children's fine motor development, and between prenatal As and Cr exposure and children's temperament development.