Environmental Health Science and Research Bureau, Healthy Environments and Consumer Safety Branch, Health Canada, 101 Tunney's Pasture Driveway, Ottawa, ON, K1A 0K9, Canada.
Faculty of Health Sciences, Simon Fraser University, Burnaby, BC, V5A 1S6, Canada.
Environ Health. 2024 Jul 1;23(1):60. doi: 10.1186/s12940-024-01095-x.
Gestational exposure to toxic environmental chemicals and maternal social hardships are individually associated with impaired fetal growth, but it is unclear whether the effects of environmental chemical exposure on infant birth weight are modified by maternal hardships.
We used data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pan-Canadian cohort of 1982 pregnant females enrolled between 2008 and 2011. We quantified eleven environmental chemical concentrations from two chemical classes - six organochlorine compounds (OCs) and five metals - that were detected in ≥ 70% of blood samples collected during the first trimester. We examined fetal growth using birth weight adjusted for gestational age and assessed nine maternal hardships by questionnaire. Each maternal hardship variable was dichotomized to indicate whether the females experienced the hardship. In our analysis, we used elastic net to select the environmental chemicals, maternal hardships, and 2-way interactions between maternal hardships and environmental chemicals that were most predictive of birth weight. Next, we obtained effect estimates using multiple linear regression, and plotted the relationships by hardship status for visual interpretation.
Elastic net selected trans-nonachlor, lead, low educational status, racially minoritized background, and low supplemental folic acid intake. All were inversely associated with birth weight. Elastic net also selected interaction terms. Among those with increasing environmental chemical exposures and reported hardships, we observed stronger negative associations and a few positive associations. For example, every two-fold increase in lead concentrations was more strongly associated with reduced infant birth weight among participants with low educational status (β = -100 g (g); 95% confidence interval (CI): -215, 16), than those with higher educational status (β = -34 g; 95% CI: -63, -3). In contrast, every two-fold increase in mercury concentrations was associated with slightly higher birth weight among participants with low educational status (β = 23 g; 95% CI: -25, 71) compared to those with higher educational status (β = -9 g; 95% CI: -24, 6).
Our findings suggest that maternal hardships can modify the associations of gestational exposure to some OCs and metals with infant birth weight.
妊娠期间接触有毒环境化学物质和产妇社会困难与胎儿生长受损单独相关，但尚不清楚环境化学物质暴露对婴儿出生体重的影响是否会受到产妇困难的影响。
我们使用了来自母婴环境化学研究（MIREC）的研究数据，这是一项在 2008 年至 2011 年期间招募的 1982 名孕妇的全加队列研究。我们从两个化学类别中量化了 11 种环境化学物质浓度 - 六种有机氯化合物（OCs）和五种金属 - 在收集的 11 种环境化学物质浓度中，有 70%以上的血液样本中检测到。我们使用出生体重调整胎龄来评估胎儿生长情况，并通过问卷调查评估了九种产妇困难。每个产妇困难变量都被二分为指示女性是否经历了困难。在我们的分析中，我们使用弹性网络来选择对出生体重最具预测性的环境化学物质、产妇困难以及产妇困难与环境化学物质之间的 2 -way 相互作用。接下来，我们使用多元线性回归获得效应估计，并为了便于解释，按困难状况绘制了关系图。
弹性网络选择了反-壬基氯、铅、教育程度低、种族少数背景和低叶酸补充摄入。所有这些都与出生体重呈负相关。弹性网络还选择了相互作用项。在环境化学物质暴露增加和报告困难的情况下，我们观察到更强的负相关和一些正相关。例如，在报告低教育程度的参与者中，每增加两倍的铅浓度与婴儿出生体重的下降更相关（β=-100g（g）；95%置信区间（CI）：-215，16），而不是那些具有较高教育程度的参与者（β=-34g；95% CI：-63，-3）。相比之下，在报告低教育程度的参与者中，每增加两倍的汞浓度与出生体重略有增加相关（β=23g；95% CI：-25，71），而不是那些具有较高教育程度的参与者（β=-9g；95% CI：-24，6）。
我们的研究结果表明，产妇困难可能会改变妊娠期间接触某些 OCs 和金属与婴儿出生体重的关系。
