先前对产前汞(Hg)暴露与继发性性别比之间关联的研究得出的结果尚无定论且相互矛盾。值得注意的是,在这种情况下,没有研究使用脐带血汞测量。此外,汞物种的差异以及硒(Se)在这种关联中的潜在修饰作用仍未被探索。使用日本环境与儿童研究的数据,我们分析了母子对与孕妇血液中总汞(THg)和硒的浓度在怀孕后期可用的数据,THG,无机汞(IHg),甲基汞(MeHg),脐带血中的硒。采用Logistic回归模型来检验Hg和Se生物标志物与继发性性别比之间的关系。在3,698名儿童的总样本中,1,877(50.8%)为男性,相当于整体次要性别比为1.03。在调整了产妇年龄和平价后,在母体血液中THg浓度与次要性别比例之间未观察到显著关联.然而,我们发现THg增加了两倍,IHg,脐带血中的甲基汞浓度与生育男性孩子的几率增加呈正相关,收益率调整后的赔率比为1.13(95CI:1.04,1.22),1.12(1.03,1.21),和1.12(1.03,1.22),分别。当按硒浓度中位数分层时,在Hg浓度和次要性别比之间的关联方面没有发现明显差异.总之,脐带血中汞浓度升高,但不是母体的血,与男性出生的可能性增加有关。
Prior research into the association between prenatal mercury (Hg) exposure and the secondary sex ratio has yielded inconclusive and conflicting results. Notably, no study has used cord blood Hg measurement in this context. Also, the differences in Hg species and the potential modifying role of selenium (Se) on this association remain unexplored. Using data from the Japan Environment and Children\'s Study, we analyzed mother-child pairs with available data for concentrations of total mercury (THg) and Se in maternal blood during late pregnancy, and THg, inorganic mercury (IHg), methylmercury (MeHg), and Se in cord blood. Logistic regression models were employed to examine the association between Hg and Se biomarkers and the secondary sex ratio. Out of the total sample of 3,698 children, 1,877 (50.8%) were male, corresponding to an overall secondary sex ratio of 1.03. After adjusting for maternal age and parity, no significant associations were observed between THg concentrations of maternal blood and the secondary sex ratio. Nevertheless, we identified that two-fold increases in THg, IHg, and MeHg concentrations in cord blood were positively associated with increased odds of having a male child, yielding adjusted odds ratios of 1.13 (95%CI: 1.04, 1.22), 1.12 (1.03, 1.21), and 1.12 (1.03, 1.22), respectively. When stratified by the median Se concentrations, no apparent differences were detected in the associations between Hg concentrations and the secondary sex ratio. In summary, elevated Hg concentrations in cord blood, but not maternal blood, were associated with an increased probability of male births.