An undescended testicle, called cryptorchidism or testicular maldescent, is a common condition in which one or both of the testes, the male reproductive glands, do not completely descend from the abdomen into the scrotum during gestation. Approximately three out of every 100 full term males are born with an undescended testicle. By the age of one, most of these testicles fully descend on their own.

The function of the testicle is to produce hormones and sperm. If the testicle is not in the “correct place,” it does not grow, develop or function correctly. Additionally, cryptorchidism is associated with testicular cancer.

Risk Factors

The exact cause of an undescended testicle is not known. Risk factors include:

  • Family history (having a father or brother with this condition)
  • Older mothers who have been exposed to toxic chemicals or are in poor health
  • Down syndrome
  • Low birth weight (less than 2.5 kilograms) or premature birth (before 37 weeks gestation)
  • Endocrine disorders


The obvious symptom is that one or both testicles are not located in the scrotum. Other abnormalities of the male genitals or urinary tract also may be present, such as an abnormal opening at the end of the penis (called hypospadia).

The undescended testicle may be:

  • In the abdomen
  • Partially descended
  • Moving in and out of the scrotum with muscle contractions (retractile). This usually requires no treatment.
  • Descended somewhere other than the scrotum (ectopic)
  • Completely absent (about 5% of cases). This may result from an abnormality in the testicular blood vessels or twisting of the testicle (testicular torsion) in utero.


The diagnosis is typically made by a physical examination. However, occasionally the diagnosis is made with a prenatal ultrasound or CT scan.


If the testis is present but does not descend on its own by six months to one year of age, treatment is usually recommended. If left unattended, the undescended testicle will not grow and develop correctly. Further, if a tumor were to develop, it could go unrecognized, as the undescended testicle is often difficult or impossible to examine.


The surgical correction of an undescended testicle is called an orchidopexy. This procedure is done under a general anesthetic, typically as an outpatient. A small incision is made in the inguinal area. The testicle is found, mobilized and placed into a position within the scrotum.  Less commonly, when the undescended testicle occupies an intra-abdominal location, a laparoscopic approach is used to assist with orchidopexy.

Hormone Therapy

On occasion, especially for bilateral undescended testicles, hormonal therapy is used. Human chorionic gonadotropin (HCG) is administered via a series of injections. With this therapy, success rates are variable and some side effects are possible.


Testicular maldescent is a common urologic problem. With appropriate and timely treatment, most patients have excellent results. All males should be assessed for this problem after birth and within the first year of life. If any testicular abnormality is found, prompt urologic evaluation is indicated.