ESPE Yearbook of Paediatric Endocrinology

Brief summary: This prospective longitudinal study compared serum reproductive hormone levels and testicular volume around the onset of puberty between cryptorchid and healthy boys.

Congenital cryptorchidism is the most common congenital anomaly among newborn boys, and still little is known about pubertal testicular function and serum reproductive hormone levels during puberty in this population.

Pubertal follow-up with clinical examination every 6 months from the age of 8.5 years was performed in a cohort of 109 patients divided in five groups: bilateral cryptorchidism with orchidopexy (OpBC, n=9), bilateral cryptorchidism with spontaneous testicular descent (SpBC, n=7), unilateral cryptorchidism with orchidopexy (OpUC, n=15), unilateral cryptorchidism with spontaneous testicular descent (SpUC, n=15) and controls (n=63). Serum samples were collected at the first visit and then every 6 months for hormone measurements (FSH, LH, total testosterone, inhibin B, SHBG, estradiol, IGF1, IGFBP-3).

Boys with bilateral cryptorchidism had higher FSH and lower inhibin B levels indicating Sertoli cell dysfunction (1). In boys with unilateral cryptorchidism, only FSH level were higher after the onset of puberty. Testosterone and LH levels were similar between groups, suggesting preserved Leydig cell function during puberty. IGF1 and IGFBP-3 levels were similar between groups.

Testicular volume was lower only in cryptorchid boys who underwent surgery, suggesting lower germ cell numbers in these boys compared to those who had spontaneous testicular descent. Lack of spontaneous testicular descent and therefore need for intervention may be a sign of testicular dysgenesis, explaining the decreased testicular volume. However, the longer time spent in an undescended position could also contribute to the progressive loss of germ cells and Sertoli cells (2).

In conclusion, cryptorchid boys, particularly after bilateral orchidopexy, showed lower levels of Sertoli and germ cell markers, whereas Leydig cell function seemed to be well-preserved during puberty.

References: 1. Andersson AM, Müller J, Skakkerbaek NE. Different roles of prepubertal and postpubertal germ cells and Sertoli cells in the regulation of serum inhibin B levels. J Clin Endocrinol Metab. 1998; 83(12):4451–4458. 2. Kollin C, Stukenborg JB, Nurmio M et al. Boys with undescended testes: endocrine, volumetric and morphometric studies on testicular function before and after orchidopexy at nine months or three years of age. J Clin Endocrinol Metab. 2012;97(12):4588–4595.