The Auxological and Metabolic Consequences for Children Born Small for Gestational Age.

'Small for gestational age' (SGA) is an auxological and not an etiological definition that characterizes children born small based upon low-birth-weight and/or birth-length criteria [≥ 2 standard deviations (SD) below the mean for gestational age]. Most SGA children exhibit catch-up growth into the normal range within 6 mo of age. Overall SGA children are 4 cm shorter than expected based upon midparental height and being born SGA is a common cause of adult short stature. Recombinant human growth hormone (rhGH) has been shown to improve adult height by 0.9 SDs and is a safe treatment. Surprisingly, a higher rhGH dose (67 μgm/kg/d) did not lead to a greater adult height than a conventional dose (33 μgm/kg/d). At least 85% of SGA children treated through childhood with rhGH achieve a height within the normal adult range. Other long-term consequences for children born SGA include insulin resistance, abdominal adiposity, dyslipidemia, type 2 diabetes mellitus, and metabolic syndrome. Cross-sectional studies have found reduced insulin sensitivity in the neonatal, childhood, and young adult periods. Increased abdominal fat has been shown in preschool SGA children and is more evident in young adults. Increased adiposity markedly accentuates reduction in insulin sensitivity. Many SGA children have suffered from in utero nutritional restriction that leads to long-term growth restriction and adverse metabolic sequelae.