Department of Communication Sciences and Disorders, Northeastern University, Boston, Massachusetts, USA.
University of Michigan School of Public Health, Department of Environmental Health Sciences, Ann Arbor, Michigan, USA.
Environ Int. 2021 Jul;152:106480. doi: 10.1016/j.envint.2021.106480. Epub 2021 Mar 16.
Infant non-nutritive suck (NNS), or sucking on a pacifier with no nutrients being delivered, has been used as in index of brain function and has been linked to subsequent neurodevelopment. Yet, no data are available connecting NNS to environmental exposures in utero. The goal of this study was to examine the relationship between gestational exposure to phthalates (a group of chemicals found in personal care products, PVC plastics, and other products) and NNS among infants in a birth cohort study in Puerto Rico.
Urinary phthalate metabolite levels were measured in women at up to three time points in pregnancy as a measure of in utero exposure to the child. We calculated the geometric mean of each metabolite for each woman as a measure of exposure across gestation. Infants had their NNS sampled using our custom research pacifier between 4-6 (± 2 weeks) weeks of age, yielding the following NNS dependent measures: cycles/burst, frequency, amplitude, bursts/min, and cycles/min.
Two hundred and eight mother-infant dyads completed this study We used multiple linear regression to assess associations between individual phthalate metabolites and NNS measurements, adjusting for infant sex, birthweight, and urinary specific gravity. An interquartile range (IQR) increase in mono carboxyisononyl phthalate across pregnancy was associated with 3.5% (95%CI: -6.2, -0.8%) lower NNS frequency and 8.9% (0.6, 17.3%) higher NNS amplitude. Similarly, an IQR increase in mono-2-ethylhexyl phthalate was also associated with 3.4% (-6.5, -0.2%) lower NNS frequency, while an IQR increase in di-2-ethylhexyl terephthalate metabolites was associated with 11.2% (2.9, 19.5%) higher NNS amplitude. Gestational exposure to phthalates may alter NNS amplitude and frequency in full-term infants. These findings indicate that the infants may be increasing their NNS amplitude to compensate for their slower NNS frequency. These preliminary findings could have important clinical implications for earlier detection of exposure-related deficits in neurofunction as well as implications for subsequent neurodevelopment and related interventions.
婴儿非营养性吸吮（NNS），即吸吮不含营养物质的奶嘴，已被用作大脑功能的指标，并与随后的神经发育有关。然而，目前尚无数据将 NNS 与宫内环境暴露联系起来。本研究的目的是在波多黎各的一项出生队列研究中，检查孕妇接触邻苯二甲酸酯（一种存在于个人护理产品、聚氯乙烯塑料和其他产品中的化学物质）与婴儿 NNS 之间的关系。
在妊娠的多达三个时间点测量女性尿液中邻苯二甲酸酯代谢物水平，作为宫内儿童暴露的衡量标准。我们为每位女性计算了每个代谢物的几何平均值，作为整个妊娠期间暴露的衡量标准。在婴儿 4-6（±2 周）周龄时，使用我们的定制研究奶嘴采集婴儿的 NNS 样本，得出以下 NNS 依赖的测量值：周期/爆发、频率、振幅、爆发/分钟和周期/分钟。
208 对母婴对完成了这项研究。我们使用多元线性回归来评估个体邻苯二甲酸酯代谢物与 NNS 测量之间的关联，调整了婴儿性别、出生体重和尿比重。妊娠期间单羧基异壬基邻苯二甲酸酯（MCNP）的四分位距（IQR）增加与 NNS 频率降低 3.5%（95%CI：-6.2，-0.8%）和 NNS 振幅增加 8.9%（0.6，17.3%）相关。同样，IQR 增加的单-2-乙基己基邻苯二甲酸酯（MEHP）也与 NNS 频率降低 3.4%（-6.5，-0.2%）相关，而二-2-乙基己基对苯二甲酸酯（DEHTP）代谢物的 IQR 增加与 NNS 振幅增加 11.2%（2.9，19.5%）相关。足月婴儿宫内邻苯二甲酸酯暴露可能会改变其 NNS 振幅和频率。这些发现表明，婴儿可能会增加其 NNS 振幅以补偿较慢的 NNS 频率。这些初步发现可能对早期发现与暴露相关的神经功能缺陷以及对随后的神经发育和相关干预具有重要的临床意义。
