Scientific Institute, IRCCS E. Medea, 0-3 Center for the at-Risk Infant, Bosisio Parini, Lecco, Italy.
NICU, Department of Clinical Sciences and Community Health, Università degli Studi di Milano, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Milan, MI, Italy.
Psychoneuroendocrinology. 2019 Feb;100:172-179. doi: 10.1016/j.psyneuen.2018.10.007. Epub 2018 Oct 12.
The co-regulation of the hypothalamic-pituitary-adrenal (HPA) axis in mother-infant dyads is thought to be key for infant and child development. Nonetheless, previous literature presents some inconsistencies that might at least partially be due to the presence of risk conditions and the use of different statistical approaches to measure HPA axis co-regulation. Very preterm (VPT) birth represents one of these risk conditions as the early foundation of mother-infant interaction is disrupted. Both VPT infants and their mothers present evidence of altered HPA axis regulation. Nonetheless, the comparison of mother-infant HPA axis co-regulation in VPT infants compared to full-term (FT) ones has not been previously investigated. In this study, 3-month-old (corrected age) VPT infants and FT counterparts with their mothers took part in a well-validated stress-inducing laboratory task (i.e., double Face-to-Face Still-Face, FFSF paradigm). Salivary cortisol samples were obtained before (Baseline) and after (Early reactivity, Late reactivity and Recovery) the FFSF procedure. Dyadic HPA axis co-regulation was assessed at each sample time-point (i.e., in-moment coupling) as well as across samples (i.e., in-time synchrony). Significant in-moment coupling emerged at Baseline, Late reactivity and Recovery for FT infants' dyads only. An overlying pattern of salivary cortisol trajectories emerged between mothers and infants in the VPT group, whereas a more complex pattern of reciprocal and complementary co-regulation was found for FT infants' dyads. Although both groups gave evidence of HPA axis co-regulation, dyads of VPT infants appear to be less able to adapt reciprocally and dynamically to stressful conditions. These findings suggest that multiple approaches to account for dyadic HPA axis co-regulation should be used in order to depict the complex pattern of biological rhythms coordination in mother-infant dyads.
母子 HPA 轴的共调节被认为是婴儿和儿童发育的关键。然而，先前的文献存在一些不一致之处，这些不一致至少部分可能是由于存在风险条件和使用不同的统计方法来测量 HPA 轴共调节。极早产儿 (VPT) 出生就是其中一种风险条件，因为母婴早期互动会被打乱。VPT 婴儿及其母亲都有 HPA 轴调节改变的证据。然而，VPT 婴儿与足月儿 (FT) 婴儿的母子 HPA 轴共调节比较尚未被研究过。在这项研究中，3 个月大（校正年龄）的 VPT 婴儿和 FT 婴儿及其母亲参加了一项经过充分验证的应激诱导实验室任务（即双面对面静止面，FFSF 范式）。在 FFSF 程序之前（基线）和之后（早期反应、晚期反应和恢复）采集唾液皮质醇样本。在每个样本时间点（即即时耦合）以及跨样本（即即时同步）评估双 HPA 轴共调节。FT 婴儿的双 HPA 轴共调节仅在基线、晚期反应和恢复时出现显著的即时耦合。VPT 组的母亲和婴儿之间出现了皮质醇轨迹重叠的模式，而 FT 婴儿的双 HPA 轴共调节则呈现出更复杂的相互和互补模式。尽管两组都有 HPA 轴共调节的证据，但 VPT 婴儿的双 HPA 轴共调节似乎不太能够对应激条件进行相互和动态的适应。这些发现表明，应该使用多种方法来描述母婴双 HPA 轴共调节，以描绘母婴双 HPA 轴共调节的复杂模式。
