Purpose of review: Most small for gestational age infants show rapid early postnatal growth and weight gain. Increasing trends towards childhood overweight and its metabolic consequences, and their epidemiological associations with lower birth weight, have led to critical assessments of the benefits and disadvantages of rapid early growth.
Recent findings: In the last 12 months, three systematic reviews have described the consistent association between rapid infancy growth and subsequent obesity risk in childhood and later life. Recent studies have also described the very early development of insulin resistance in small for gestational age children who show catch-up growth, and this insulin resistance may, in turn, adversely affect body composition, growth and puberty. Long-term randomized trials of growth hormone therapy, however, remind us of the persisting short stature and significant adult height deficit in untreated children without early spontaneous catch-up.
Summary: Even in modern societies with low rates of childhood infection and mortality, the small for gestational age infant may face a dilemma over whether or not to catch up. Current nutritional strategies that promote catch-up growth should include some monitoring of weight-for-length and adiposity, and the concept of 'healthy catch-up growth' should be the goal of future research.