Risk factors for cryptorchidism

Abstract

The condition known as cryptorchidism – undescended testis – is one of the most common congenital abnormalities found among males, and is one of the few known risk factors for testicular cancer (TC). Like testicular cancer, the key exposures in the occurrence of cryptorchidism remain elusive. Testicular descent is thought to occur during two hormonally-controlled phases – between 8–15 weeks and 25–35 weeks gestation – and while it is clear that a failure of testes to descend permanently is likely due to disruptions to one or both of these phases, the cause(s) and mechanism(s) of such disruption are still unclear. In this manuscript, we review the broad range of putative risk factors that have been evaluated in relation to the development of cryptorchidism to date, discuss their plausibility, and make suggestions regarding further approaches to understand aetiology. There are few exposures for which there is consistent evidence of an association with cryptorchidism; and in those cases where evidence appears unequivocal – for example, the relationship between cryptorchidism and gestational measures such as low birth weight – the measured exposure is likely to be a surrogate for the true causal exposure. The relative importance of each risk factor may vary considerably between mother/son pairs depending on an array of genetic, maternal, placental and foetal factors – all of which could vary between regions.

Cryptorchidism in Boys With Cerebral Palsy Is Associated With the Severity of Disease and With Co-Occurrence of Other Congenital Anomalies

“…While both presentations were more common in singletons, that association was not retained in the final model for CAs (Table 6). Cryptorchidism risk in both this study and the general non-CP population (28, 29) is associated with decreased gestational age. In contrast, we found an increased frequency of other CAs in children with CP born near term, as reported previously (1, 11).…”

“…Our results suggest that cryptorchidism is more likely to occur in cases of CP associated with other CAs and with IUGR, a known strong risk factor for both non-syndromic cryptorchidism (28, 29) and for CP (30, 31). Reciprocally, we also identified cryptorchidism and IUGR as independent variables associated with the occurrence of other CAs in cases of CP.…”

Study of Ras/MAPK pathway gene variants in Chilean patients with Cryptorchidism

“…The incomplete descent of one or both testes through the inguinal canal into the scrotum, a developmental anomaly known as cryptorchidism (DOID: 11383), is observed in approximately 1–9% of all boys at birth (Ghirri et al ., ; Wagner‐Mahler et al ., ; Gurney et al ., ). At one year of life, due to spontaneously descent, only 1% of boys will still have cryptorchidism (Barthold & González, ).…”

E2F1 copy number variations contribute to spermatogenic impairment and cryptorchidism by increasing susceptibility to heat stress

“…Furthermore, patients affected by microdeletion or microduplication syndrome have been reported to be at higher risk of undescended testes among syndromic features (Kashevarova et al, 2014;Hu et al, 2017), suggesting that structural variations might contribute to the etiology of cryptorchidism. Indeed, the possible involvement of genetic factors in human cryptorchidism constitutes the research topic of many studies in recent years (Gurney et al, 2017). On the other hand, genetic causes are increasingly being discovered to be associated also with idiopathic spermatogenic impairment and male infertility (Tournaye et al, 2017).…”