POSTNATAL-GROWTH AND MENTAL-DEVELOPMENT - EVIDENCE FOR A SENSITIVE-PERIOD

For many years it has been suspected that severely impaired somatic gr owth during early postnatal life can be associated with the subsequent impairment of mental abilities. This study aimed to test that hypothe sis on the basis of data gathered from a prospective whole population survey of infant development in south London. A year's birth cohort of 1558 full-term singletons was monitored; 47 otherwise healthy cases w ith serious growth faltering in the first year were recruited. Mental and psychomotor abilities were assessed at 15 months. Potentially conf ounding psychosocial variables, including cognitive stimulation receiv ed at home, were measured contemporaneously. A statistical model was c onstructed that enabled the timing, duration and severity of growth fa ltering to be used as predictors of mental functioning. Up to 37% of t he variance in cognitive and psychomotor outcome at 15 months can be e xplained by the model. The first few postnatal months appear to consti tute a ''sensitive period'' for the relationship between growth and me ntal development.