A FOLLOW-UP STUDY OF PHYSICAL GROWTH FOLLOWING FAILURE TO THRIVE WITH SPECIAL REFERENCE TO A CRITICAL PERIOD IN THE FIRST YEAR OF LIFE

This was a follow-up study of physical growth of children who have had failure to thrive. It comprised 77 children in whom the cause was corrected and 35 children with persistent organic cause together with 10 children in whom the patent ductus arteriosus was ligated after the first year. The treated group consisted of surgical and medical cases. Their pattern of growth was compared with that of a control group composed of 75 children from the fracture clinic and 24 siblings, all from the same age range and nearly the same mean age. Seven parameters of growth were tested. Significant retardation in six parameters was noted in both the treated group (in which the cause of failure to thrive was removed) and the untreated group (in which the treatment of the cause was impossible). In the treated group, the mean skeletal age was less retarded than the mean height, while the mean head circumference of females was significantly more retarded than that of males. There was only slight difference between early and late ligation of patent ductus arteriosus in subsequent physical growth. Neither the very early onset of failure nor its severity caused a severe retardation within the treated group. Prolonged duration of failure to thrive or failure to correct the cause in the first year led to significant subsequent growth retardation within the treated group. Parental height and birth weight played a less well defined role, while socio-economic environment played a minor role in causing growth retardation in the treated group. The first year can only be regarded as a relatively critical period concerning subsequent physical growth due to difficulty in separating the effect of illness from that of genetic endowment. Growth retardation may represent another congenital abnormality independent of the original anomaly which was corrected. The importance of reduced cell number was discussed.