Infant physiological regulation and maternal risks as predictors of dyadic interaction trajectories in families with a preterm infant.

This longitudinal study examined predictors of rates of growth in dyadic interaction quality in children born preterm who did not experience significant neurological findings during neonatal intensive care unit (NICU) hospitalization. Multiple methods were used to collect data from 120 preterm infants (48% girls, 52% boys) and their mothers. Infant heart rate variability (HRV), gestational age, neonatal health, feeding route, and maternal socioeconomic (SES) risks were assessed at NICU discharge (mean of 36 weeks postconception). Mother-child interactions were observed at 4, 9, 16, and 24 months postterm and analyzed with hierarchical linear modeling. On average, children's quality of play, interest, and attention increased over time while their dysregulation and irritability decreased, whereas average maternal positive affect and involvement declined in quality (ps < .05), although there was individual variation in rates of change. Mothers of infants with higher postfeeding HRV (i.e., vagal regulation) exhibited less decrease in positive affect and involvement between 4 months and 24 months, compared with mothers of infants with lower HRV (p < .05). Although infants with higher postfeeding HRV showed less positive affect and communication at 4 months, they exhibited significantly greater increases in positive affect and social competence and decreases in dysregulation and irritability between 4 months and 24 months, compared with infants with lower HRV (ps < .05). Dyads experiencing more SES risks showed less optimal interactions at 4 months; this difference remained as children grew older (ps < .05). Results have implications for our understanding of social development in preterm infants.