Department of Earth and Environmental Sciences, University of Texas, Arlington, TX, USA.
Department of Public Health Sciences, University of California, Davis, CA, USA; UC Davis MIND (Medical Investigations of Neurodevelopmental Disorders) Institute, Sacramento, CA, USA.
Environ Res. 2021 May;196:110939. doi: 10.1016/j.envres.2021.110939. Epub 2021 Feb 26.
BACKGROUND/OBJECTIVE: Per- and polyfluoroalkyl substances (PFAS) have neurobehavioral toxicity in experimental studies. Evidence on associations between prenatal PFAS exposure and child's cognitive development is inconsistent partly due to differences in assessment time points and tools. We examined associations of prenatal maternal serum PFAS concentrations with child's cognitive development assessed at multiple time points in infancy and toddlerhood.
We included 140 mother-child pairs from MARBLES (Markers of Autism Risk in Babies - Learning Early Signs), a longitudinal cohort of children with a first degree relative who was diagnosed with autism spectrum disorder followed from birth. Study children's cognitive development was assessed at 6, 12, 24, and 36 months of age using the Mullen Scales of Early Learning (MSEL) which provides an overall Early Learning Composite (normative mean of 100 and SD of 15) and four subscales (i.e., fine motor, visual reception, receptive language, and expressive language abilities; normative mean of 50 and SD of 10). Nine PFAS were quantified in maternal serum collected during pregnancy. We examined associations of log 2-transformed prenatal maternal serum PFAS concentrations with the MSEL Composite and each of the subscale scores at each time point as well as longitudinal changes in the scores over the four time points. We also classified trajectories into low- and high-score groups and fit Poisson regression models to estimate associations expressed as relative risks (RR).
Among six PFAS detected in more than 60% of the samples, prenatal maternal serum perfluorooctanoate (PFOA) was inversely associated with child's Composite score at 24 months (β = -5.22, 95% CI: -8.27, -2.17) and 36 months of age (β = -5.18, 95% CI: -9.46, -0.91), while other five PFAS were not strongly associated with Composite score at any time points. When assessing longitudinal changes in the scores over the four time points, PFOA was associated with trajectories having a negative slope for Composite scores and all four subscales. When examining trajectories of the scores between low- and high-score groups, PFOA was associated with having lower and/or decreasing Composite scores (RR = 1.49, 95% CI: 1.09, 2.03).
Prenatal PFOA appears to adversely affect child's cognitive development in toddlerhood in this study population. Because a large fraction of MARBLES children is at risk for atypical development, population-based studies are needed to confirm our findings.
背景/目的：全氟和多氟烷基物质（PFAS）在实验研究中具有神经行为毒性。部分由于评估时间点和工具的不同，产前 PFAS 暴露与儿童认知发育之间的关联证据不一致。我们研究了产前母体血清 PFAS 浓度与婴儿期和幼儿期多次认知发育评估之间的关系。
我们纳入了来自 MARBLES（婴儿自闭症风险的标志物 - 早期学习迹象）的 140 对母婴对，这是一个纵向队列，其中儿童的一级亲属被诊断为自闭症谱系障碍，并从出生开始进行随访。研究儿童的认知发育在 6、12、24 和 36 个月时使用 Mullen 早期学习量表（MSEL）进行评估，该量表提供了一个整体的早期学习综合得分（正常均值为 100，标准差为 15）和四个分量表（即精细运动、视觉接收、接受性语言和表达性语言能力；正常均值为 50，标准差为 10）。在妊娠期间采集母体血清，共检测了 9 种 PFAS。我们研究了母体血清中 log2 转化的产前 PFAS 浓度与 MSEL 综合得分以及每个子量表得分在每个时间点的关系，以及四个时间点的评分纵向变化。我们还将轨迹分为低得分组和高得分组，并拟合泊松回归模型，以估计表示为相对风险（RR）的关联。
在 60%以上样本中检测到的六种 PFAS 中，产前母体血清全氟辛烷磺酸（PFOA）与 24 个月（β=-5.22，95%CI：-8.27，-2.17）和 36 个月时儿童的综合得分呈负相关年龄（β=-5.18，95%CI：-9.46，-0.91），而其他五种 PFAS 与任何时间点的综合得分均无明显关联。当评估四个时间点的评分纵向变化时，PFOA 与综合评分和所有四个分量表的负斜率轨迹相关。当检查低得分组和高得分组之间的得分轨迹时，PFOA 与较低和/或降低的综合得分相关（RR=1.49，95%CI：1.09，2.03）。
在本研究人群中，产前 PFOA 似乎对幼儿期儿童的认知发育产生不利影响。由于 MARBLES 儿童中有很大一部分存在非典型发育的风险，因此需要进行基于人群的研究来证实我们的发现。
