Kabamba M, Tuakuila J
Faculty of Sciences, University of Kinshasa, Democratic Republic of Congo.
Faculty of Sciences, University of Kinshasa, Democratic Republic of Congo; Faculty of Health Sciences, University of Sherbrooke, Quebec, Canada.
Toxicol Lett. 2020 Oct 10;332:20-26. doi: 10.1016/j.toxlet.2020.06.007. Epub 2020 Jun 20.
The aim of this study was to summarise the available information regarding the partition of toxic metal (Cd, Hg, Mn, Pb) levels in the maternal/foetal unit from large epidemiological studies. We performed a systematic search of PubMed/MedLine, EMBASE, and ISI Web of Science for papers on Cd, total Hg, Mn or Pb levels in the maternal/cord blood that were published in English (n > = 200; 2010-2017). Data on year of publication, sample size, location, year of survey, and main results were extracted. We found a total of 35 papers. Most studies included large convenience samples of healthy pregnant women. The maternal/cord blood was properly used as a biomarker of prenatal exposure to toxic metals. The partition of these toxic metal levels in the maternal/foetal unit was metal-specific. Cd median levels (IQR) in cord blood reported worldwide were much lower [∼ 70 % < LOD = ± 0.11 μg/L] than those found in maternal blood [0.23 μg/L (0.15-0.35), ∼ 65 % > LOD]. Considering that Cd was under LOD in 70 % of the cord blood, Cd cord:maternal ratio as well as Cd cord proportion were not provided. Total Hg median levels (IQR) in cord blood [0.75 μg/L (0.40-1.19), ∼30 % < LOD = ±0.35 μg/L] were usually higher than in maternal blood [0.55 μg/L (0.40-0.85), ∼ 10 % < LOD = ±0.15 μg/L]. Hg cord:maternal ratio was 1.34 (1.00-1.91), and infants born would have Hg cord:(cord + maternal) proportion ranged from 0.50 to 0.63. Mn was the only metal that was detected in 100 % in both maternal (LOD : ±0.50 μg/L) and cord (LOD = ±0.2 μg/L) blood. Mn median levels (IQR) in cord blood [32.96 μg/L (26.90-40.10)] were 2 times higher than in maternal blood [14.01 μg/L (11.50-17.58)]. Mn cord:maternal ratio was 2.35 (1.09-3.80), and infants born would have Mn proportion ranged from 0.52 to 0.79. Pb median levels (IQR) in cord blood [5.79 μg/L (4.34-8.38), ∼ 5% < LOD : ±2.07 μg/L] were usually equal to or lower than those reported in maternal blood [8.07 μg/L (5.79-10.76), ∼ 1% < LOD = ±1.03 μg/L]. Pb cord:maternal ratio was 0.71 (0.59-0.96), and infants born would have Pb proportion ranged from 0.37 to 0.49. Globally, the results indicate that total Hg and Mn levels were lower in maternal blood but higher in cord blood. However, much greater variability was seen with Cd and Pb. At delivery, total Hg and Pb levels in maternal blood were strong predictors of cord blood levels. Our findings empty that understanding the partition, levels and correlations of toxic metals in the maternal/cord blood may help to elucidate the adverse effects of these metals on foetuses and neonates.
本研究的目的是总结大型流行病学研究中有关母胎单位中毒性金属（镉、汞、锰、铅）水平分配的现有信息。我们在PubMed/MedLine、EMBASE和ISI Web of Science中进行了系统检索，以查找2010 - 2017年以英文发表的关于母血/脐血中镉、总汞、锰或铅水平的论文（n≥200）。提取了发表年份、样本量、地点、调查年份和主要结果的数据。我们共找到35篇论文。大多数研究纳入了大量健康孕妇的便利样本。母血/脐血被恰当地用作产前接触毒性金属的生物标志物。这些毒性金属在母胎单位中的水平分配具有金属特异性。全球范围内报道的脐血中镉的中位数水平（四分位间距）远低于母血中的水平[约70%＜检测限=±0.11μg/L]，母血中镉的中位数水平为0.23μg/L（0.15 - 0.35），约65%＞检测限。鉴于70%的脐血中镉低于检测限，未提供镉的脐血:母血比值以及镉的脐血比例。脐血中总汞的中位数水平（四分位间距）[0.75μg/L（0.40 - 1.19），约30%＜检测限=±0.35μg/L]通常高于母血中的水平[0.55μg/L（0.40 - 0.85），约10%＜检测限=±0.15μg/L]。汞的脐血:母血比值为1.34（1.00 - 1.91），出生婴儿的汞脐血:(脐血 + 母血)比例在0.50至0.63之间。锰是唯一在母血（检测限:±0.50μg/L）和脐血（检测限 = ±0.2μg/L）中100%都能检测到的金属。脐血中锰的中位数水平（四分位间距）[32.96μg/L（26.90 - 40.10）]是母血中水平[14.01μg/L（11.50 - 17.58）]的2倍。锰的脐血:母血比值为2.35（1.09 - 3.80），出生婴儿的锰比例在0.52至0.79之间。脐血中铅的中位数水平（四分位间距）[5.79μg/L（4.34 - 8.38），约5%＜检测限:±2.07μg/L]通常等于或低于母血中报道的水平[8.07μg/L（5.79 - 10.76），约1%＜检测限 = ±1.03μg/L]。铅的脐血:母血比值为0.71（0.59 - 0.96），出生婴儿的铅比例在0.37至0.49之间。全球范围内，结果表明母血中总汞和锰的水平较低，但脐血中较高。然而，镉和铅的变异性更大。分娩时，母血中总汞和铅的水平是脐血水平的强预测指标。我们的研究结果表明，了解母血/脐血中有毒金属的分配、水平和相关性可能有助于阐明这些金属对胎儿和新生儿的不良影响。
