SUN-182 Testicular Function and Inguinal Testicular Position at Baseline are Independent Predictors of Hormonal Treatment Success in Prepubertal Boys with Cryptorchidism

Abstract Disclosure: S.P. Martin Benitez: None. E. Monteverde: None. R. Grinspon: None. R.A. Rey: None. Background: Cryptorchidism is a frequent complaint in boys. The choice between surgical and hormonal treatments may vary according to the etiology. The efficacy of human chorionic gonadotropin (hCG) therapy varies from <10% to >50% between different series. The aim of this study was to detect factors associated with therapeutic success of hCG to bring testes down to the scrotum in prepubertal boys. The primary hypothesis was that impaired testicular function at baseline, defined as serum AMH <3rd centile for age, is a risk factor for unsuccessful treatment, defined as testes not reaching the scrotum after 1 weekly injection of hCG 1000 IU im or sc for 5 weeks. Methods: We performed a retrospective case-control study in a single center between 2000 and 2020. Based on a pilot study, considering that the incidence of treatment success is 10% in boys with impaired testicular function, and establishing a confidence level of 99% and a power of 90% for an odds ratio (OR) of 3, the estimated sample size was 112 for each group. Results: A total of 260 boys with cryptorchidism were analyzed: 136 with successful (controls) and 124 with unsuccessful (cases) hCG treatment. Median ages (IQR) were 4.7 (3.1-7.2) years and 4.4 (2.8-7.0) years (p=0.45), respectively. Baseline serum AMH was 698 (520-931) and 248 (169-579) pmol/L (p<0.001). The relative prevalence of impaired testicular function was 5.9% and 56.5% (p<0.001), with an OR (95% CI) of 25.5 (11.2-65.1). The relative prevalence of high inguinal position of the testes before hCG was 8.1% and 54.0% (p<0.001), with an OR of 16.7 (7.8-39.0). No differences between the groups were found in baseline FSH or in the relative prevalences of congenital or acquired cryptorchidism, being born small for gestational age or the existence of inguinal hernia. A multivariate analysis did not detect a statistically significant interaction between impaired testicular function and inguinal position of the testes. Conclusion: Low serum AMH and high inguinal testicular position were independent predictors of unsuccessful hCG treatment for cryptorchidism in prepubertal boys, allowing clinicians to consider each factor separately when assessing treatment prognosis. These findings also highlight serum AMH as a key marker for pretreatment assessment, as it reflects the functionality of Sertoli cells and the ability of the testes to respond to hCG stimulation. Presentation: Sunday, July 13, 2025