Leptin and ghrelin are hormones involved in the regulation of appetite and adiposity. Leptin suppresses appetite and induces weight loss; ghrelin stimulates appetite and promotes weight gain. The study reported in this thesis was designed to examine the relationship of cord blood leptin and ghrelin with milk intake over the first week of life, and with infant growth up to twelve weeks of age. One hundred term formula fed newborns were recruited at birth. Leptin and ghrelin were measured in cord blood by radioimmunoassay. Milk intake was measured by weighing of bottles of formula milk before and after feeding. Measurements of weight, length and head circumference were taken at birth, seven days and at twelve weeks of age. A number of control variables were also measured. Birthweight was a significant predictor of mean milk intake, which rose significantly from days 1 to 7, with no difference between males and females. Weight gain or loss in the early neonatal period was a direct and significant consequence of milk intake consumed over that period. There was no relationship between cord blood leptin or ghrelin (controlling for birthweight) on the infants' milk intake over the first 24 hours of life or on their mean milk intake over the first week of life. Weight gain was significantly correlated with birthweight, with higher birthweight associated with lower weight gain. There was no relationship between cord leptin and weight gain to three months of age after adjusting for birthweight; but lower cord ghrelin levels were significantly associated with slower weight gain.

A prospective, longitudinal and observational study, using a non-clinical population of mother-child dyads was carried out to evaluate the comparable contribution of maternal psychopathology, cognitions, infant temperament and interactional behaviour to infant feeding difficulties throughout the first year of life. This thesis also explores the specificity of maternal insensitivity associated with feeding difficulties, and evaluates the longitudinal stability of maternal cognitions and psychopathology from pregnancy to the first postnatal year. Maternal unhealthy core beliefs, mediated by low maternal self-esteem, in addition to infant temperament, were paramount in the prediction and maintenance of infant feeding problems. Even during pregnancy, certain core beliefs predicted the development of later feeding problems. 1n addition, difficult infant behaviour, and insensitive maternal behaviour were associated with feeding difficulties. Moreover, between pregnancy and the first six postnatal months maternal anxiety decreased, and between 6 and 12 months postpartum disordered eating attitudes decreased. Conversely, negative self-sacrifice core beliefs increased between pregnancy and the first six postnatal months. This thesis demonstrates many interesting and novel findings but primarily, through the utilisation of longitudinal data; it exemplifies the important causal contribution that maternal unhealthy core beliefs, mediated by maternal self-esteem, have in the development of early infant feeding problems.

No description available.

No description available.