Department of Neonatology, Karolinska Institute, Stockholm, Sweden.
Birth Defects Res. 2019 Sep 1;111(15):1087-1109. doi: 10.1002/bdr2.1530. Epub 2019 Jun 3.
Maternal-neonate separation for human newborns has been the standard of care since the last century; low birth weight and preterm infants are still routinely separated from their mothers. With advanced technology, survival is good, but long-term developmental outcomes are very poor for these especially vulnerable newborns. The poor outcomes are similar to those described for adversity in childhood, ascribed to toxic stress. Toxic stress is defined as the absence of the buffering protection of adult support. Parental absence has been strictly enforced in neonatal care units for many reasons and could lead to toxic stress. The understanding of toxic stress comes from discoveries about our genome and epigenetics, the microbiome, developmental neuroscience and the brain connectome, and life history theory. The common factor is the early environment that gives (a) signals to epigenes, (b) sensory inputs to neural circuits, and (c) experiences for reproductive fitness. For human newborns that environment is direct skin-to-skin contact from birth. Highly conserved neuroendocrine behaviors determined by environment are described in this review. The scientific rationale underlying skin-to-skin contact is presented: autonomic development and regulation of the physiology leads to emotional connection and achieving resilience. Maternal-neonate separation prevents these critical neural processes from taking place, but also channel development into an alternative developmental strategy. This enables better coping in a stressful environment in the short term, but with permanently elevated stress systems that negatively impact mental and physical health in the long term. This may explain the increasing incidence of developmental problems in childhood, and also Developmental Origins of Health and Disease. Arguments are presented that maternal-neonate separation is indeed a source of toxic stress, and some suggestions are offered toward a "zero separation" paradigm.
自上个世纪以来，母婴分离一直是新生儿护理的标准做法；低体重儿和早产儿仍然会被常规地与母亲分开。随着先进技术的发展，这些特别脆弱的新生儿的存活率很高，但长期的发育结果却非常差。这些不良结果与儿童时期逆境所描述的结果相似，归因于毒性应激。毒性应激是指缺乏成人支持的缓冲保护。出于多种原因，新生儿护理病房一直严格执行父母不在场的规定，这可能导致毒性应激。对毒性应激的理解来自于我们对基因组和表观遗传学、微生物组、发育神经科学和大脑连接组以及生命史理论的发现。共同的因素是早期环境，它给(a) 表观基因传递信号，(b) 为神经回路提供感官输入，(c) 为生殖适应性提供经验。对于人类新生儿来说，这种环境是从出生开始的直接皮肤接触。本综述描述了由环境决定的高度保守的神经内分泌行为。提出了皮肤接触的科学依据：自主发展和生理调节导致情感联系，并实现韧性。母婴分离阻止了这些关键的神经过程的发生，但也将发育引导到另一种发育策略。这使得在短期内更好地应对压力环境，但长期来看，压力系统会永久升高，从而对身心健康产生负面影响。这可能解释了儿童时期发育问题发生率的增加，也解释了健康与疾病的发育起源。提出了母婴分离确实是毒性应激的来源的论点，并提出了一些建议，朝着“零分离”范式发展。
