Histrelin Implantation and Growth Outcomes in Children With Congenital Adrenal Hyperplasia: An Institutional Experience.

Background: Children with congenital adrenal hyperplasia (CAH) because of 21 hydroxylase deficiency (21OHD) are at risk for early or precocious puberty and a short adult height compared to population means and midparental height. The effect of histrelin in suppressing puberty and improving growth in these children has not been reported.

Methods: Retrospective cohort analysis of all patients (age ≤ 20) at our institution who underwent histrelin implantation between 2008 and 2017. Treated patients with CAH (classic and nonclassic forms of 21OHD) were identified and their growth data analyzed.

Results: Fifteen children with CAH were treated with histrelin for a median of 3 years (range 2-5; age at first implantation 7.7 ± 1.5 years). Bone age (BA) to chronologic age (CA) decreased from 1.57 ± 0.4 to 1.25 ± 0.25 ( < .01), while predicted adult height (PAH) increased by 7.1 ± 6.6 cm ( < .01). A subgroup of 10 children reached adult height. Similar changes in BA/CA and PAH were observed with therapy ( = .02). Adult height z improved compared to pretreatment PAH z (-1.42 ± 0.9 vs. -1.96 ± 1.1 respectively, < .01), but remained lower than midparental height z ( = .01).

Conclusion: In this retrospective cohort study of children with CAH due to 21OHD and early or precocious puberty, histrelin implantation resulted in a decrease in BA progression compared to CA and an improvement in PAH. In the subgroup who completed growth, adult height remained significantly lower than midparental. These results need to be confirmed with prospective controlled studies.