The aim of the study: to evaluate the impact of size at birth and postnatal growth on anthropometry, pubertal development, body composition, metabolic and cardiovascular functions, hormonal profile and bone mineral density in adolescence. Objectives: 1) to assess growth pattern and growth factors in children born small for gestational age (SGA) from birth to adolescence in comparison with children born appropriate for gestational age (AGA); 2) to compare pubertal development, gonadal sizes and sex hormones in adolescents born SGA and AGA in relation to early growth; 3) to explore components of metabolic syndrome (fat mass and its distribution, glucose metabolism, lipid profile and cardiovascular function) and cortisol secretion in adolescents born SGA and AGA in relation to early growth; 4) to assess the impact of vitamin D, parathormone and calcium levels, pubertal development, size at birth and early growth on bone mineral density in children born SGA and AGA. This study is a continuation of the prospective long-term follow-up case-control study, in which growth of study children was followed from birth to adolescence. Study revealed that SGA-born adolescents are more prone to central adipose tissue distribution, worse glucose tolerance, lower bone mineral density and have increased risk for short stature. Girls born SGA have higher levels of markers of biochemical hyperandrogenism and smaller uterine and ovarian sizes.