Do all girls with apparent idiopathic precocious puberty require gonadotropin-releasing hormone agonist treatment?

OBJECTIVE

To evaluate prospectively pubertal and predicted adult height progression until final height (FH) or near FH in girls with apparent idiopathic precocious puberty who were not treated.

STUDY DESIGN

The decision not to treat at the time of initial evaluation was based on evidence of slowly progressive puberty as shown by bone age (BA) advancement <2 years above the chronologic age, whatever the hypothalamic pituitary ovarian axis activation, or no evidence of hypothalamic pituitary ovarian axis activation, whatever the BA advancement. During follow-up, patients who showed a significant decrease in predicted FH were treated with gonadotropin-releasing hormone agonist.

RESULTS

Twenty-six girls with idiopathic precocious puberty were studied at a mean chronologic age of 7.4 +/- 0.9 years during a follow-up period of 6.6 +/- 2.2 years until FH or near FH. During the first 2 years of follow-up, most of the patients (group 1, n = 17; 65% of the cases) showed no substantial changes in predicted FH. They never required treatment, and menarche occurred at a mean chronologic age of 11.9 +/- 0.6 years. Their mean FH (or near FH) at 160.7 +/- 5.7 cm was close to their target height (161.3 +/- 4.7 cm). On the other hand, after a mean follow-up period of 1.4 +/- 0.8 years, 9 patients (group 2) had acceleration of bone maturation and deterioration of their predicted FH (from 162.1 +/- 6. 2 cm to 155.3 +/- 5.6 cm; P <.01), which was at that time significantly lower than their target height (P <.05) (mean target height = 159.8 +/- 4.6 cm). They received a gonadotropin-releasing hormone agonist for 2.1 +/- 0.7 years, resulting in a restoration of growth prognosis (mean FH or near FH = 160.2 +/- 6.7 cm).

CONCLUSIONS

This study demonstrates that not all patients with apparent idiopathic precocious puberty require medical treatment, notably when there is no evidence of hypothalamo-pituitary ovarian activation or no significantly advanced BA to impair height potential. Most show a slowly progressing puberty. However, careful follow-up of these patients is necessary up to at least 9 years of age, because until then height prediction may deteriorate, necessitating gonadotropin-releasing hormone agonist treatment in one third of the cases.