Interventions such as kangaroo care (KC) and live-performed music therapy (LPMT), are increasingly used to facilitate stress reduction in neonates. This study aims to investigate the effect of combining the two on physiological responses and neurological functioning in very preterm infants. Infants received six sessions of LPMT. KC was added to one LPMT session. Physiological responses included heart rate, respiratory rate and oxygen saturation. We videotaped infants for 30 min before and after two sessions to assess general movements (GMs). We included 17 infants, gestational age median 26.0 weeks (IQR 25.6–30.6 weeks), of whom six were males. Combined interventions showed a decrease in heart rate from mean 164 bpm before to 157 bpm during therapy, p = 0.001. Oxygen saturation levels increased during combination therapy from median 91.4% to 94.5%, p = 0.044. We found no effects of LPMT or combined interventions on GMs. Infants with a postnatal age (PNA) 7 days. In conclusion, combining interventions is equally beneficial for physiological stability and neurological functioning as LPMT alone. Future studies should focus on the effects of this combination on parent-infant bonding.

The young developing brain is very sensitive to many environmental influences, both positive and negative. Parental stress and parent-infant bonding have been shown to be associated with neurodevelopmental delays in toddlers. However, it is not known at what age these associations become relevant which we aim to study as early as three-months of age, paving the way for new intervention strategies. This study included 339 parent-infant dyads or triads from the Dutch TRAILS-NEXT cohort. Parental stress and parent-infant bonding were assessed at three months of age using the 'Nijmeegse Ouderlijke Stress Index - Korte versie' (NOSI-K) and Postpartum Bonding Questionnaire (PBQ), respectively. Infant neurodevelopment was assessed using the General Movement Assessment (GMA), including the Motor Optimality score - Revised (MOS-R). Perinatal risk factors with known associations with infant neurodevelopment were included as potential confounders. 210 infant-mother dyads and 147 infant-partner dyads were included in the main analysis. Parental stress levels were elevated in 7 % of mothers and 18 % of partners, but no significant correlations were found between parental stress, bonding, and MOS-R scores. After adjustments for confounders, neither parental bonding nor stress showed significant relationships with general movement characteristics in regression analyses, suggesting that other factors may influence individual differences in early motor development. Parental stress and parent-infant bonding were not associated with infant neurodevelopment at age of three months, suggesting a wider window of opportunity to intervene in case of parental stress or suboptimal parent-infant bonding.