Performance of adult height prediction methods in 6 to 8-year-old girls with GnRH-dependent precocious puberty.

Abstract

Objectives: In girls with precocious puberty (PP), adult height prediction (PAH) is crucial in treatment planning, yet the estimations may be prone to inaccuracies. This study aimed to compare the accuracy of two commonly used PAH methods in 6-8-year-old girls diagnosed with idiopathic GnRH-dependent PP.

Methods: This retrospective study included data on 60 six- to eight-year-old girls diagnosed with PP. Data was collected from medical records. Forty-eight (82 %) girls were treated with GnRH analogues, and 18 (30 %) had data on AH. Bone ages (BA) were assessed with Greulich-Pyle and BoneXpert. PAHs were estimated with Bayley-Pinneau and BoneXpert.

Results: In girls treated with GnRH-analogue, AH did not significantly differ from the mean PAH calculated by Bayley-Pinneau (mean difference, -0.1 cm ± 6.6 cm (SD); p=0.93). Predicted adult height estimated by BoneXpert was higher than the actual AH (-3.6 cm ± 4.6 cm, p=0.01), but it showed lower variability in individual prediction errors and less bias related to the degree of BA advancement than Bayley-Pinneau. All subjects reached their mid-parental target height range.

Conclusions: In 6- to 8-year-old girls with signs of idiopathic GnRH-dependent precocious puberty, the potential to reach their growth target remains, and overestimation of residual height growth at diagnosis should be carefully considered before initiating treatment.