Center for Environmental and Health Sciences, Hokkaido University, North-12, West-7, Kita-ku, Sapporo 060-0812, Japan.
Department of Social Medicine, Asahikawa Medical University, Midorigaoka-higashi 2-1-1-1, Asahikawa 078-8510, Japan.
Environ Int. 2019 Apr;125:418-429. doi: 10.1016/j.envint.2019.01.051. Epub 2019 Feb 8.
It is necessary to determine whether there are adverse health effects of prenatal exposure to long-term, low levels of mercury and selenium. However, there are limited that reports on the association between mercury levels by selenium levels and birth size. Therefore, we examined whether maternal mercury levels during pregnancy had any effect on infant birth size, and size, and whether selenium levels influenced this relationship.
To examine the association between mercury and selenium levels during pregnancy with infant birth size.
The Japan Environment and Children's Study is a prospective birth cohort conducted between 2011 and 2014. Total mercury levels and total selenium levels in maternal blood during the second and third trimesters were measured using Inductively Coupled Plasma-Mass Spectrometry. Birth weight and small-for-gestational-age were confirmed by medical records. Small-for-gestational-age was defined as birth weight below the 10th percentile according to standard percentile for gender, parity, and gestational age. Multiple linear and logistic regression analyses were used to examine the association between maternal mercury exposure and birth weight or small-for-gestational-age adjusted for confounders (including maternal age and body mass index pregnancy).
Overall, 15,444 pregnant women were included in this study. Median (inter-quartile range) of blood mercury and selenium levels were 3.66 (2.59-5.18) ng/g and 170.0 (158.0-183.0) ng/g, respectively. Compared to infants of mothers with the highest blood selenium level, those of mothers with the lowest blood selenium level had neither a significant birth weight increase (9 g, 95% confidence interval: -6, 25) nor a significant odds ratio for small-for-gestational-age (0.903, 95% confidence interval: 0.748, 1.089). Compared to infants of mothers with the lowest blood mercury level, those of mothers with the highest blood mercury level had neither a significant birth weight reduction (-12 g, 95% confidence interval: -27, 4) nor a significant odds ratio for small-for-gestational-age (0.951, 95% confidence interval: 0.786, 1.150). Compared to infants of mothers with the lowest quartile of maternal blood mercury level, all infants of mothers with the highest quartile of maternal blood mercury level had a reduced birth head circumference of 0.073 cm (95% confidence interval: -0.134, -0.011).
There was no association between maternal blood mercury levels and small-for-gestational-age and birth weight among 15,444 pregnant women. In a Japanese population, which has a relatively higher blood mercury level than reported in Western population, reduced birth size was not found to be associated with blood mercury levels, with the exception of birth head circumference.
有必要确定产前长期低水平接触汞和硒是否对健康有不良影响。然而，关于汞水平与硒水平与出生体重之间关系的报告有限。因此，我们研究了妊娠期间母亲的汞水平是否会对婴儿的出生体重和大小产生影响，以及硒水平是否会影响这种关系。
研究妊娠期间汞和硒水平与婴儿出生体重之间的关系。
日本环境与儿童研究是一项在 2011 年至 2014 年期间进行的前瞻性出生队列研究。使用电感耦合等离子体质谱法测量了母亲在妊娠第二和第三阶段的血液总汞和总硒水平。通过医疗记录确认出生体重和小于胎龄儿。小于胎龄儿定义为出生体重低于按性别、产次和胎龄计算的第 10 百分位数。使用多元线性和逻辑回归分析，在调整混杂因素（包括母亲年龄和体重指数）后，研究了母亲汞暴露与出生体重或小于胎龄儿之间的关系。
共有 15444 名孕妇纳入本研究。血液汞和硒水平的中位数（四分位距）分别为 3.66（2.59-5.18）ng/g 和 170.0（158.0-183.0）ng/g。与母亲血硒水平最高的婴儿相比，母亲血硒水平最低的婴儿出生体重增加不显著（9g，95%置信区间：-6，25），小于胎龄儿的比值比也不显著（0.903，95%置信区间：0.748，1.089）。与母亲血汞水平最低的婴儿相比，母亲血汞水平最高的婴儿出生体重无显著降低（-12g，95%置信区间：-27，4），小于胎龄儿的比值比也无显著降低（0.951，95%置信区间：0.786，1.150）。与母亲血汞水平最低四分位数的婴儿相比，母亲血汞水平最高四分位数的所有婴儿出生头围均缩小 0.073cm（95%置信区间：-0.134，-0.011）。
在 15444 名孕妇中，母亲血汞水平与小于胎龄儿和出生体重之间没有关联。在一个血液汞水平相对高于西方人群报告的日本人群中，除了出生头围外，未发现出生大小与血液汞水平有关。
