Catch-up growth after prolonged hypothyroidism.

This report presents an analysis of four patients who suffered from longstanding untreated hypothyroidism, with special attention to the phase of catch-up growth after the start of L-thyroxine treatment. Although a permanent height loss could not be prevented, the capacity to establish a remarkable catch-up growth spurt proved to be still intact, even after a long period of thyroid dysfunction. Catch-up growth in hypothyroidism may be incomplete if treatment has been started shortly before or during puberty.