Background: One of the most important concerns parents have about their daughters’ precocious puberty is the reduction in final height. This study evaluates the changes in predicted adult height (PAH) over time in girls with early puberty. Materials and Methods: Girls with aged 7 to 9.5 years old with the beginning of puberty after seven years were evaluated. Two non-dominant hand x-ray were taken at 6 to 24 months. The predicted adult height (PAH) was estimated using bone age and the Bayley-Pinneau method. Changes in PAH were determined. The relationship between age, height and weight at birth, target height and puberty stages, and bone age and BMI with PAH changes were investigated. Results: Seventy girls with a mean age of 8.23 years (SD: 0.65) and an average time interval of 0.99 years (SD: 0.47) were studied. At the first evaluation, the average bone age was 8.6 years (p value=0.225 SD: 1.25), and the average predicted adult height was 158.95 cm (SD: 5.66). At the second evaluation, the average bone age was 10.06 years (P-value=0.15 SD: 1.36), and the average predicted adult height was 158 cm (SD: 6.75). The mean difference in predicted adult height is -0.94 ± 4.8 cm. The mean final height predicted in the first and second visits showed a significant relationship with PAH changes and in the group that increased PAH by more than 3 cm, the average growth rate was 69.7 cm per year. In other words, the group growth velocity was higher, the higher their PAH. Two factors associated with expected adult height changes were found: height growth velocity and bone age velocity. Conclusion: Girls with early puberty are not altogether at risk of reduced adult height. However, if there is concern about reducing final height, the expected adult height will still need to be re-estimated at the appropriate interval.

Background: Predicting the final height in children with idiopathic short stature is essential for starting growth hormone therapy. This study was conducted to assess final height estimation variability over time. Materials and Methods: In this cross-sectional study, children with idiopathic short stature were examined. Bone age and final height were estimated through the Greulich-Pile and Bayley-Pinneau method. This process repeated in the later visits with at least six months, and the results were compared statistically. The patients were classified based on the changes in predicted final height (PFH). Results: A total of 81 patients (46 boys, 35 girls) with a mean age of 11.09 years were enrolled. The calculated PFH in the first visit was 160.15±8.79 cm, which has decreased to 159.33±9.38 cm. Based on the second evaluation, 43 patients had few changes in PFH (±3 cm), 23 patients experienced a decrease in PFH of more than 3 cm, and 15 patients experienced an increase in PFH of more than 3 cm. A change in Tanner stage, weight gain, height velocity, target height, and the interval between the two evaluations were similar in all groups. Young under ten years had more decreasing in the PFH. Conclusion: Depending on bone age velocity, predicting the final height can change over time. As bone age velocity increases, PFH decreases more. PFH is also less reliable at younger ages and requires monitoring of growth and puberty and repeating final estimations later in life.