Child Maltreatment Severity and Sleep Variability Predict Mother-Infant RSA Coregulation.

Regulatory processes underlie maternal-infant interactions and may be disrupted in adverse caregiving environments. Child maltreatment and sleep variability may reflect high-risk caregiving, but it is unknown whether they confer vulnerability for poorer mother-infant parasympathetic coordination. The aim of this study was to examine mother-infant coregulation of respiratory sinus arrhythmia (RSA) in relation to child maltreatment severity and night-to-night sleep variability in 47 low-income mother-infant dyads. Maternal and infant sleep was assessed with actigraphy and daily diaries for seven nights followed by a mother-infant Still Face procedure during which RSA was measured. Higher maltreatment severity was associated with weakened concordance in RSA coregulation related to the coupling of higher mother RSA with lower infant RSA, suggesting greater infant distress and lower maternal support. Additionally, higher infant sleep variability was associated with infants' lower mean RSA and concordance in lagged RSA coregulation such that lower maternal RSA predicted lower infant RSA across the Still Face procedure, suggesting interrelated distress. Findings indicate that adverse caregiving environments differentially impact regulatory patterns in mother-infant dyads, which may inform modifiable health-risk behaviors as targets for future intervention.