Dyadic co-regulation, affective intensity and infant's development at 12 months: A comparison among extremely preterm and full-term dyads.

Extremely low gestational age children (ELGA, born below 28 weeks of GA) represent the most at-risk preterm group in terms of survival, developmental sequelae and rates of impairment and cognitive delays. However, the impact of an extremely preterm birth on mother-infant co-regulation and affective intensity which may affect early infant's development has not been investigated. Based on a relational dynamic system approach, our study aimed to investigate the quality of co-regulation and affective intensity during spontaneous play interaction in 20 mother-infant ELGA dyads compared to 20 full-term (FT) dyads at 12 months (corrected age for ELGA infants). Relationships between the quality of dyadic co-regulation and the infant's level of cognitive, motor and language development were also investigated. The quality of dyadic co-regulation was assessed using the Revised Relational Coding System (R-RCS) by Fogel et al. (2003), the mothers' and infants' affective intensity was coded using a coding system by Lunkenheimer, Olson, Hollenstein, Sameroff, and Winter (2011). Infants' development was assessed using the Bayley Scales (BSID-III, 2006). With respect to FT dyads, ELGA dyads were characterised by less frequent symmetric and more frequent unilateral co-regulation patterns and by less positive and more neutral affective intensity of both infants and mothers. Cognitive, motor and language scores were lower in ELGA infants than in FT infants. Symmetrical co-regulation was related to motor scores in ELGA infants, and to cognitive scores in FT infants. Our findings contribute to the literature by demonstrating the difficulties of ELGA mother-infant dyads at 12 months in sharing the symmetric co-regulation and positive affective intensity and how symmetric co-regulation is strictly related to motor development in ELGA infants. Based on these findings, intervention programmes to foster joint attention, active involvement and positive affective intensity in ELGA dyads and infants' development in the first year of life should be designed.