The majority of children born small for gestionational age (SGA), approximately 85-95%, achieve catch-up growth by two years of age. [Lee: 2003] [Houk: 2012] For most children who achieve catch-up growth, this happens within the first six months postnatally. Approximately 10%-15% of SGA children do not experience catch-up growth by the age of two. This height deficit continues through childhood and in almost all cases results in adult short stature. [Houk: 2012] Catch-up growth is generally considered rare after the age of two years.

The optimal timing for GH therapy initiation in short stature children born small for gestational age lies between two to four years of age. [Houk: 2012] Short stature SGA children who do not achieve catch up growth by 2 years of age should be referred to endocrinology for timely evaluation and initiation of growth hormone treatment if eligible.

Timely initiation of growth hormone therapy is important for reasons of both efficacy and cost. [Chatelain: 2007] Delayed initiation of growth hormone treatment results in increased costs due to the subsequent requirement of larger dosing and longer treatment duration. Delayed initiation of treatment is also associated with a significantly decreased lower height increase attainment . Noted trends are better efficacy in children who remain prepubertal throughout the treatment period, greater growth response in children with a larger height deficit, and better growth response the younger the child is at the start of treatment.

Although growth hormone therapy can improve linear growth, the decision to treat is complex. The therapy is costly and can have side effects as well as cause pain to the child receiving growth hormone injections. Referral to a pediatric endocrinologist is helpful for enabling a robust discussion of the benefits and risks of therapy and obtaining prior authorization for therapy, if needed. See Premature Infant Follow-Up.