• Cognitive development;
  • follow-up-studies;
  • gender differences;
  • newborn infant;
  • neonatal behaviour

The purpose of this study was to investigate whether the level of self-regulation in the newborn baby (a) predicts later cognitive and social development, (b) correlates to duration of breastfeeding and (c) has an impact on sleeping rhythm and the infant's autonomic behaviour. The study involved 38 full-term infants of optimal health who were assessed at an age of 3 d using a screening instrument measuring neonatal self-regulation, low, ordinary and high. The instrument, a conditional global scale, developed on the basis of the items in the Neonatal Behavioral Assessment Scale, identifies three levels of self-regulation. Thirty-six of the infants participated in a follow-up study at 2 y of age, when they were tested with Griffiths' Mental Developmental Scales and one of the parents was interviewed about length of breastfeeding, sleeping habits and the infant's autonomic behaviour. The results showed that the level of self-regulation was correlated to 3 out of 5 variables (Personal-Social development, Hearing & Speech and Eye & Hand Coordination) in the Griffiths test. The results also indicated differences in sleeping rhythm as well as in breastfeeding patterns between the three groups. Furthermore, the study indicated gender-based differences in the level of neonatal self-regulation and confirmed previous findings of gender-based differences in achieved developmental level at 2 y of age assessed with Griffths' Mental Developmental Scales.

Conclusion: The findings in this study indicate that infants with a low level of self-regulation are at risk for poorer social and cognitive development as well as regulatory disorders.