Maternal distress across the postnatal period is associated with infant secretory immunoglobulin A

Developmental Cascades Link Maternal-Newborn Skin-to-Skin Contact with Young Adults' Psychological Symptoms, Oxytocin, and Immunity; Charting Mechanisms of Developmental Continuity from Birth to Adulthood

Premature birth disrupts the continuity of maternal-newborn bodily contact, which underpins the development of physiological and behavioral support systems. Utilizing a unique cohort of mother-preterm dyads who received skin-to-skin contact (Kangaroo Care, KC) versus controls, and following them to adulthood, we examined how a touch-based neonatal intervention impacts three adult outcomes; anxiety/depressive symptoms, oxytocin, and secretory immunoglobulin A (s-IgA), a biomarker of the immune system. Consistent with dynamic systems' theory, we found that links from KC to adult outcomes were indirect, mediated by its effects on maternal mood, child attention and executive functions, and mother-child synchrony across development. These improvements shaped adult outcomes via three mechanisms; (a) "sensitive periods", where the infancy improvement directly links with an outcome, for instance, infant attention linked with higher oxytocin and lower s-IgA; (b) "step-by-step continuity", where the infancy improvement triggers iterative changes across development, gradually shaping an outcome; for instance, mother-infant synchrony was stable across development and predicted lower anxiety/depressive symptoms; and (c) "inclusive mutual-influences", describing cross-time associations between maternal, child, and dyadic factors; for instance, from maternal mood to child executive functions and back. Findings highlight the long-term impact of a birth intervention across development and provide valuable insights on the mechanisms of "developmental continuity", among the key topics in developmental research.

Formation of local immunity in infants on different types of feeding

Rational feeding from the early days of life programs the health, growth and development of the child over the following years. By the age of 6 months children on artificial feeding are reliably more likely to form excess body weight. The nature of nutrition depends on the condition of the overall and local immune protection of the child. Application of non-invasive methods for determining sIgA (in oral fluid (saliva), in coprofiltrate) allows to assess local immunity in infancy age. Breastfed infants receive sIgA with mother’s milk and have additional protection against the pathogens of respiratory and intestinal infections. The level of sIgA in the mother’s breast milk can be determined to assess the condition of children’s immunity. Children on breastfeeding experience acute respiratory diseases less often compared to children fed with adapted milk formula.