Relation Between Birth Condition and Neuro-Behavioral Organization in the Neonate

The neuro-behavioral organization of three groups of infants who differed in their condition at birth as determined by their Apgar score was examined during the first week of life. At the time of testing, all infants, regardless of birth status, were in good condition according to clinical evaluation. Testing consisted of the presentation of 30 lateralized somesthetic stimuli to the perioral region of each infant (15 to each side). The response measure used was the lateral direction of the first head turn. As a group, normal infants (Apgar scores of 9–10) were found to be more responsive to stimulation of the right than of the left, and to make more ipsilateral responses to stimulation of the right than of the left. Infants whose condition at birth was poor (Apgar scores 1–6) did not show these patterns of response but were equally likely to be preponderantly responsive to stimulation at either side. The degree of lateral differentiation was atypically small even for those infants of poor birth status who exhibited the typical direction of differentiation, i.e., who made more ipsilateral responses to stimulation of the right than of the left. Furthermore, the proportion of infants of poor birth status who made any contralateral responses was higher than the proportion of normal infants who made such responses. Results from a group of infants whose condition at birth was questionable (Apgar scores 7–8) fell between those from the extreme groups with respect to all of the analyses.

Speculation:

Poor condition at birth has persistent effects on behavioral organization even in babies who, in clinical judgment, have recovered normal functioning. To the extent that early behavioral organization may be relevant to the subsequent development of lateral differentiation, these effects could be related to the association between a variety of disabilities and disturbances in lateral differentiation which has been found in older children and adults.