The short normal child : influences on the growth pathway and final height outcome

• Main Author: Mulligan, Jean
• Other Authors: Betts, Peter ; Bailey, Brian
• Published: University of Southampton 2002
• Subjects: 612; Physiology
• Online Access: https://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273753

Short stature is a common reason for a child to be referred for specialist opinion. Most will have no underlying pathology but dismissing a short child as normal may impose future suffering as the short adult is perceived to be psychosocially disadvantaged and to face greater health risks. Adult height, however, cannot be predicted from childhood height with any degree of certainty. Growth begins at the moment of conception and ends with epiphyseal closure some two decades later. Height, however, is not accumulated at a fixed rate throughout the growing process but consists of four distinct phases: foetal, infancy, childhood and pubertal. The intensity and duration of each phase is subject to wide variation and poor growth in any one phase does not inevitably compromise final height. To a large extent, both stature and the tempo of growth are genetically determined but social and environmental factors can have a modifying effect. For some children, poor environmental conditions can cause growth to falter but equally an improvement in quality may result in catch-up growth. The Wessex Growth Study is the first study to follow the growth of an unselected population of short normal children from school entry until final height together with controls of'average' height. A great deal of background information was also collected for each child including parental heights, birth history, social & family background, and medical history. To determine which short normal children become short adults this thesis has compared the patterns of growth of short normal children with their average height controls and assessed the impact of genetic and environmental variables on the growth pathway and final height. Before puberty, short children grew more slowly than those who are taller but the magnitude and duration of the pubertal spurt and the adolescent height gain were similar for short and control girls, and for short and control boys. The pubertal spurt of short normal boys, however, occurred, on average, some six months later than expected. Interestingly, although short normal girls had similar birth weights, skeletal delay and were just as likely as short normal boys to be considered short for family, the timing, magnitude and duration of their pubertal spurt were comparable with the control girls and with Tanner's standards. The mean height centile of both groups improved suggesting a continuing secular trend in adult stature within the UK. Nevertheless, the increase in relative height was greater for the short children implying some degree of catch-up growth, especially for boys. Indeed, short normal girls were three times more likely than short normal boys to attain an adult height below the 0.4^ centile and below their genetic potential. Some short children have become taller adults than others but in relation to their peers, a substantial number have remained short and failed to reach their genetic potential. Growth is influenced by many factors, genetic, social, environmental and emotional, but few variables were found to be predictors of the adult height of short normal children and much of the variance remains unexplained. This thesis demonstrates the individuality of the growth pathway and the difficulty in identifying those who will become short adults. Recognising which children might benefit from intervention requires a multi-professional team including the growth specialist, social worker and psychologist.