Early Initiation of rhGH Therapy Significantly Improves Height Gain and Reduces the Gap to Target Height in Children Born Small for Gestational Age: A Multicenter Retrospective Study

Background: Treatment with recombinant human growth hormone (rhGH) is approved for children born small for gestational age (SGA) who fail to show postnatal catch-up growth; however, optimizing its efficacy remains a challenge. Aim: to evaluate the impact of rhGH therapy on growth trajectory (GT) and adult height (AH) in SGA children and to identify factors influencing height gain (HG). Methods: A total of 49 SGA children (24 males, 25 females) without postnatal growth recovery and treated with rhGH were enrolled. Clinical and anthropometric data were collected at treatment initiation (T0), after 1 (T1) and 2 years (T2) of therapy, at pubertal onset (P0), during the first (P1) and second year (P2) of puberty, and at attainment of AH. Parameters included age, bone age, H, weight, BMI (all expressed as SDS), HG, and the difference between H and target height (Δ H-TH). Results: a significant increase in HG at all evaluated stages was observed (p < 0.05). The H–TH difference progressively decreased from T0, particularly until the first two years of puberty. Nevertheless, mean AH was −1.75 ± 0.63 SDS, and it was found to fall within the TH range in 86% of cases. Univariate and multivariate regression analysis revealed that age and H at T0 were independent predictors of HG. Conclusions: rhGH treatment has a positive impact on GT in children born SGA. Pubertal growth has a limited contribution in influencing AH of these patients. H and timing of treatment initiation significantly influence HG in SGA children. Early selection of patients for rhGH therapy could further improve their GT.