NUTRITION IN FRAGILE LIFE PHASES: FERTILITY, PREGNANCY AND HOSPITALIZED CHILDREN

This thesis deals with nutrition and diet, during the most fragile phases of life: fertility, pregnancy and hospitalized children. The duplex aim of this thesis is to investigate the dietary habits of subfertile couples attempting a pregnancy and the effects of bad nutrition on growth and metabolism in hospitalized children. It is divided into theoretical and experimental parts. The theoretical part studies firstly, the determinants of reproductive factors that influence male and female fertility and, secondly, the importance of maintaining a good nutritional status during hospital recovery in a pediatric population. The topic approached in this thesis belongs to a public health field since delivering and guarantee a good nutritional state in all ages of life is known to be crucial in the prevention of both under and overnutrition, which have both negative effects on long-term health. In the first experimental part, three studies that investigate data from a cohort of subfertile couples, presenting to the Infertility Unit of Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan, are described. The aim is to analyze dietary and lifestyle habits of both males and females that may affect fertility. Dietary habits have been collected with the use of a previously validated Food Frequency Questionnaire. The results showed that a moderate alcohol intake appears associated with better semen quality in the male sample. While there is evidence to support that alcohol does have an impact on fertility, it is also difficult to establish a definitive link as there is no standard “drink” or comparative way to measure alcohol consumption. We could not analyze the role of heavy or binge drinking, which are consistently associated to detrimental effects on semen quality. Regarding female fertility, in literature there is evidence of a lower risk of in vitro fertilization failure in women reporting higher adherence to Mediterranean Diet. The analysis here described does not show a statistically significant effect of Mediterranean Diet on oocyte quality and success rate after assisted reproductive techniques. In the second experimental part, The Italian Pediatric Nutrition Survey which analyzed data from many Italian pediatric hospitals is presented, and metabolic data of children recovered in the Pediatric Unit of Fondazione IRCCS Ca’ Granda, Ospedale Maggiore Policlinico, Milan are discussed. The aim of this this second part is to show how much pediatric malnutrition is still unrecognized in hospital setting, where, an accurate nutritional and metabolic evaluation should be recommended. Strong evidences suggest that nutrition modulates the capacity to exit from the state of stress and disease, with possible repercussions on growth and development and nutrition imbalances may affect the prognosis during hospital stay. In the national survey a high prevalence of both acute and chronic malnutrition among hospitalized pediatric patients in Italy emerges, especially in infants and young children and nutritional support is only given to a small number of the malnourished children. In disease condition, the metabolic response to stress is highly variable and cannot be easily predicted, consequently it is difficult to predict the right amount of calories and nutrients that a child needs starting from the calculation of the resting energy expenditure. In this thesis was demonstrated that the commonly employed equations, WHO, Harris-Benedict, Schofield, and Oxford formulae should not be used to estimate metabolism in hospitalized children. Feeding strategies based on these equations might result in unintended underfeeding or overfeeding. The development and validation of more accurate equations will be an initial step in precipitating a culture shift which places greater emphasis on the importance of nutritional delivery as a therapeutic intervention, rather than supportive care.