Skin-to-skin holding in relation to white matter connectivity in infants born preterm

Preterm birth is associated with altered white matter development and long-term neurodevelopmental impairments. Skin-to-skin care (kangaroo care) has well-documented benefits for physiological stability and bonding, but its association with neonatal brain structure remains unclear. This study explored the association between in-hospital skin-to-skin care and neonatal white matter microstructure in frontal and limbic pathways that are linked to stress regulation and socio-emotional development, processes potentially influenced by affective touch during skin-to-skin care.

This retrospective study analyzed electronic medical records and diffusion MRI data collected from 86 preterm infants (<32 weeks gestational age) in a single NICU. Skin-to-skin care exposure was quantified as total duration (minutes/instance) and rate (minutes/day) of sessions. Diffusion MRI scans obtained before hospital discharge assessed mean diffusivity (MD) and fractional anisotropy (FA) in the cingulate, anterior thalamic radiations (ATR), and uncinate fasciculus. Hierarchical regression models examined associations between skin-to-skin care and white matter microstructure, adjusting for gestational age, health acuity, postmenstrual age at scan, and MRI coil type. Sensitivity analyses controlled for socioeconomic status and NICU visitation frequency.

Skin-to-skin care duration was positively associated with MD in the cingulate (B = 0.002, p = 0.016) and ATR (B = 0.002, p = 0.020). Skin-to-skin care rate was also positively linked to MD in the ATR (B = 0.040, p = 0.041). Skin-to-skin care duration and rate were not associated with FA in the cingulate but skin-to-skin duration and rate were negatively associated with FA in the ATR (duration: B = -0.001, p = 0.020; rate: B = -0.017, p = 0.008). No significant associations were found for the uncinate fasciculus. Findings remained robust after adjusting for socioeconomic status and visitation frequency.

This study provides novel evidence linking in-hospital experiences of skin-to-skin care to neonatal white matter development. These findings have important implications for understanding how family-centered neuroprotective practices, such as skin-to-skin care, may affect brain development to improve long-term developmental outcomes.