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Nurture in the neonatal intensive care unit

In their excellent review, Kommers et al. (1) use a novel approach to answer an important question: Why do maternal licking, grooming and separation have such a big effect on bonding? In summarising an impressive body of physiological research, the authors conclude that optimised parent–infant bonding can overcome negative impacts of premature birth, and that such efforts should be increased in the neonatal intensive care unit (NICU). While acknowledging the limitations of Bowlby’s theoretical construct, the authors strive to unite their analyses into it. The authors touch upon the concept of coregulation. However, they limit discussion to regulation of the infants by their mothers. In fact, the infant also regulates the mother’s physiology (e.g. suckling-related oxytocin release, skin temperature during skin-to-skin holding, physiological responses to crying). Co-regulation between mother and infant in close physical contact during nurture activities, such as holding and nursing, has survival advantage and serves to maintain homoeostasis in both. Clinical observations during family nurture interventions led me to the conclusion that the static psychological constructs of ‘bonding’ do not adequately describe the normal, dynamic mother–infant relationship. Rather, I view biological co-regulation as underlying the formation and maintenance of an emotional connection between the two. In this light, I was able to understand dysregulated behaviour as being related to the absence of co-regulation, and thereby formulate a clear path to its remedy. Mothers can be ‘bonded’ to their infants, but not necessarily spend significant time in states of co-regulation and emotional connectedness. This leaves the child vulnerable to dysregulation. Despite identifying the existence of co-regulation of the infant by the mother, bonding theorists place an emphasis on self-regulation, a state that too often dissolves into dysregulation, which interferes with energy homoeostasis, optimal learning and interrelating. Morelius posits that shared environment increases concordance of the pair’s hypothalamic pituitary adrenal (HPA) axis reactivity (2). Nonetheless, sharing an environment does not in itself guarantee co-regulation of physiological states. In our randomised control NICU trial of the Family Nurture Intervention, many mothers were judged to be emotionally disconnected (e.g. visibly removed or distracted from the infant during skin-to-skin contact). However, asking the mothers to express their emotional upset directly to their infants was repeatedly observed to result in dramatic changes in behavioural states in both infant and mother. Hearing the mother’s expression of upset emotion, infants often became alert and made eye contact. The mothers typically responded with enlivened engagement and expressed feeling a deep connection, often for the first time. More useful to NICU neonatologists, nurses and parents are three questions: (i) Are the mother and infant coregulating and emotionally connected? (ii) Upon emotional upset, how easily do the mother and infant regain this connection? (iii) How can a mother–infant pair achieve/ maintain emotional connection? Meeting one another’s needs is key to emotional connection. Our hypothesis is that infants with met needs have increased co-regulation with their mothers and less dysregulation when the mother is absent. Establishment of a Calming Cycle routine, during which the pair achieves a state of mutual calm and co-regulation, is the target of Family Nurture Intervention. The nurture science field struggles to explain mother– child interactions within Bowlby’s psychological, central nervous system framework. It is clear that early experiences can affect the hypothalamic–pituitary–adrenal axis, but we may better understand the underlying mechanisms by studying early life experiences at the level of subcortical, hormonal and autonomic nervous system (ANS) activities. Kommers and co-authors cite Hofer’s ‘hidden regulators’ (3) and the licking and grooming methylation research of Meaney and colleagues (4) to explain the nurture phenomenon. I agree that these are examples of basic behavioural and molecular mechanisms that underlie the powerful effects of nurture. However, I believe these mechanisms exert their actions at the subcortical rather than psychological cortical levels. Thepowerful physiological effects ofNICUhospitalisation on themother and baby, as documented byGrunau et al. (5), are best understood in the context of subcortical emotional connection and co-regulation. Fundamentally, the evolutionarily conserved Pavlovian-conditioning mechanism effects on bodily functions result in high/low survival and adaptive/maladaptive behaviours. This conditioning mechanism, which begins in utero and continues after birth, assures survival and adaptive behaviour. Pavlovian conditioning may be the foundational mechanism underlying