Keep on track: Monitoring growth and development in children born preterm and full-term

Environmental factors in early life influence early development and growth, and influence long-term health. In this thesis we showed that in premature infants, the length and growth of the cerebral cortex (corpus callosum) is a good marker of brain growth and a predictor of later neurological development. An eye-tracking test (watching a video) at the age of 1 year also appeared to be a predictive factor for overall cognitive and motor development 1 year later. We also found that weight gain after preterm birth is associated with body composition in childhood. We also compared 2 methods of measuring body composition in children (DXA and ADP) and found that the results of fat mass (percentage) and fat-free mass at 3-5 years of age differ significantly between both methods, and that these differences are greater in very preterm children compared to full-term children. We present improvements to the algorithm to improve results with ADP. We also investigated sleep and found that parent-reported sleep characteristics and problems are similar between very preterm and full-term children at the age of 3 years. In the general population, we have shown that low birth weight (<2500 grams) and growth retardation during fetal life and childhood are associated with longer sleep duration and higher sleep efficiency at 10-15 years of age. Furthermore, at the same school age, greater intraday variability (fragmentation of the 24-hour activity rhythm) was associated with a higher fat mass index and higher visceral fat mass in boys.