Evolution of neonatal behavior assessment scale scores in the first month of life

There is little information available about behavioral differences between the sexes and behavioral variability in the neonatal period. The aim of this report was to assess the individual behavioral changes in the first month of postnatal life using the Brazelton Neonatal Behavior Assessment Scale. A total of 89 healthy and full-term newborns took part in a voluntary study, in which they were evaluated with the BNBAS at 3 days and 4 weeks of age. The mother's anxiety level and other biological and sociocultural variables were also collected. No significant differences were observed between the sexes but the evolution between 3 days and 4 weeks of age in the orientation and autonomic clusters was different between girls and boys. The habituation and range of state cluster scores were stable during the time assessed in both sexes and were not influenced by any variables. The increase in orientation cluster scores was associated significantly with the mother's age. The results show that there is variability only on some BNBAS item clusters, which suggests that these items are more influenced by interaction with the environment. (C) 2003 Elsevier Science Inc. All rights reserved.