Infertility and Cryptorchidism

Cryptorchidism is a condition in which one or both of the testes become arrested somewhere along their path of migration from the posterior abdominal wall to the scrotum. It is one of the most frequent congenital birth defects in male children and represents an important risk factor for infertility and testicular cancer. Approximately 2–4% of full-term newborns are born with at least one cryptorchid testis. In preterm births, the rate increases to about 30%. Normal testicular descent is a process largely governed by a carefully orchestrated hormonal symphony. The transabdominal phase is characterized by the descent of the testes into the lower abdominal position, which is primarily governed by INSL3. The inguinoscrotal phase describes the passage of the testes through the inguinal canal and into the scrotum and is largely governed by androgens. By understanding the normal physiology of testicular descent, the location of the undescended testes can shed light on which processes were interrupted. There are a variety of genetic and environmental risk factors that can impact the precise timing and coordination of these processes, resulting in cryptorchidism. Understanding the pathophysiology is important because the main complications associated with cryptorchidism are infertility and cancer. Timely treatment can minimize the risk of developing these complications. Current treatment focuses on hormonal and surgical methods in order to direct the testes in the favorable environment of the scrotum.