Objective. We assessed in a retrospective unicenter study the impact of treatment with GnRH analogues (GnRHa) on adult height (AH), body mass index (BMI), bone mineral density (BMD) and reproductive function in girls with idiopathic central precocious puberty (ICPP).

Patients. 87 ICPP patients were treated with GnRHa for 4.2 ± 1.6 yr (range 3 - 7.9) and observed for 9.9 ± 2.0 yr (range 4 - 10.6 yr) after discontinuation of treatment; to better estimate the efficacy 32 comparable ICPP untreated girls were analyzed.

Results. AH was 159.8 ± 5.3 cm, significantly higher than pre-treatment predicted AH (PAH) either for accelerated or for average tables of Bayley and Pinneau. The gain in cm between pre-treatment PAH and AH was 5.1 ± 4.5 cm and 9.5 ± 4.6 cm respectively. Hormonal values, ovarian and uterine dimensions, reduced during treatment, increased to normal after 1 year without therapy. Age of menarche was 13.6 ± 1.1 yr with an interval of 0.9 ± 0.4 yr after therapy. Menstrual pattern was normal. Six girls became pregnant and delivered normal offspring. BMISDS for CA increased, not significantly, before, during and after therapy. BMD at discontinuation of treatment was significantly lower and increased to control values after gonadal activity resumption.

Conclusions. GnRHa treatment in ICPP is safe for reproductive system, BMD and BMI and helpful in reaching AH close to TH, however the variability of individual response suggests that one choose more parameters than increment in height, especially in girls with pubertal onset over 8 years of age.