QUESTIONS OF EVALUATION OF POSTNATAL GROWTH IN PRETERM CHILDREN. PART 2. CATCH-UP GROWTH IN PRETERM INFANTS
The term «catch-up growth» is now widely used in neonatology and pediatrics to describe the growth of preterm infants. Catch-up growth - is a compensatory strengthening of the body''s growth after a period of slow growth. The lower the gestational age of the premature baby, the more intense catch-up growth is in the future. Catch-up growth is considered to be an important criterion for evaluating of nursing of preterm infants. Formation of catch-up growth is seen as a favorable outcome. Evaluation of catch-up growth is carried out with the use of percentiles and standard deviations (Z-score). Catch-up growth has a positive effect on neurological outcome. Catch-up growth is considered complete if the growth rates are between 5 and 10 percentile. The values of growth are satisfactory if they are located at the 10th percentile and above. Catch-up growth is complete if a standard deviation is greater than minus 2 (Z-score). The optimal parameters are considered to be located within two standard deviations of the mean. Appropriate estimation of the growth should be carried out weekly. Growth curves help to determine when the catch-up growth begins. After discharge from the hospital catch-up growth continues. Catch-up growth occurs within the first year of life. The critical period for catch-up growth is considered to be the first 6 months of life. Subsequently, the growth rate decreases. The growth is not sufficient, if the values are below the 3 percentile. About 50% of the causes of impaired growth are due to the shortage of supply. Premature babies can have problems with nutrition after discharge from the hospital. The very rapid growth may lead to the development of metabolic syndrome in later life. Low birth weight is associated with increased risk of hypertension, stroke, and diabetes. Compensatory growth is often accompanied by excessive deposition of fat. In assessing of the growth it is necessary to accommodate the growth of muscle mass and fat mass. Maintaining optimal growth rate is important for the prevention of metabolic syndrome. A meta-analysis of all published growth curves for premature babies is needed to determine the optimal postnatal growth.