Cryptorchidism is the medical term for an undescended testicle, a condition where one or both testicles have not moved into their normal position in the scrotum before birth. It is the most common genital condition present at birth in boys, affecting roughly 1 in 30 full-term male infants. While many cases resolve on their own in the first few months of life, persistent cryptorchidism requires medical attention because it carries real risks for fertility and testicular health if left untreated.
What Is Cryptorchidism Causes? Risks And Treatment
During fetal development, testicles form inside the abdomen. In the last few months of pregnancy, they normally travel down a pathway called the inguinal canal into the scrotum. When that journey does not complete, the testicle remains somewhere along the path — inside the abdomen, in the groin, or high in the scrotum.
Doctors do not always know why this happens. Hormones from the mother and the baby guide testicular descent, so any disruption in those signals can interfere. Premature birth is the strongest known risk factor because the descent often happens late in pregnancy. Low birth weight and family history also increase the chance.
How Common Is Undescended Testicle?
About 3 percent of full-term baby boys are born with at least one undescended testicle. In premature infants the rate is much higher — some studies report rates above 30 percent — because these babies have had less time in the womb for the testicles to descend.
Many of these testicles descend on their own. By the time a baby reaches 3 to 6 months of age, most undescended testicles have moved into the scrotum naturally. If a testicle has not descended by 6 months, spontaneous descent becomes unlikely. At that point the condition is considered persistent and treatment is typically recommended.
What Are the Main Causes?
The exact cause is often unknown, but several factors are clearly linked to cryptorchidism.
Prematurity is the most common factor. Testicular descent usually occurs between the 28th and 35th week of gestation. Babies born before this window have simply not had enough time for the process to finish.
Hormonal factors matter as well. Normal testicular descent depends on testosterone and other hormones produced by the fetus. Conditions that affect hormone production or sensitivity can prevent descent. This includes some genetic conditions that affect the pituitary gland or the testes themselves.
Genetics play a role. A boy whose father or brother had cryptorchidism has a higher chance of having it too. Several genes involved in testicular development and hormone signaling have been identified as contributing factors, though no single gene explains most cases.
Maternal factors during pregnancy may also contribute. Some research suggests that maternal obesity, diabetes, and exposure to certain environmental chemicals may increase risk, but the evidence for these factors is less definitive than for prematurity or genetics.
Why Does It Matter? Understanding the Risks
An undescended testicle is not just an anatomical difference. The testicle is designed to function at a temperature slightly lower than core body temperature, which the scrotum provides. When a testicle remains inside the abdomen or groin, it is exposed to higher temperatures that can damage the cells responsible for sperm production.
Fertility problems are the most significant long-term concern. Studies consistently show that men who had bilateral cryptorchidism — both testicles undescended — have lower sperm counts and higher rates of infertility. Men who had one undescended testicle also face increased risk, though less severe. The risk of fertility problems increases the longer the testicle remains undescended.
Testicular cancer risk is also elevated. Men with a history of cryptorchidism have a higher risk of developing testicular cancer compared to men without the condition. The increased risk applies to both the undescended testicle and, to a lesser extent, the normally descended one. Early surgery reduces but does not eliminate this risk, so ongoing awareness remains important.
Other complications include inguinal hernia, which occurs more frequently in boys with cryptorchidism because of the open passage the testicle leaves behind. Torsion — a painful twisting of the spermatic cord that cuts off blood supply — is also more common in undescended testicles. Trauma is a greater concern when the testicle is located in the groin rather than protected in the scrotum.
How Is Cryptorchidism Diagnosed?
Diagnosis usually happens during a routine newborn examination. The doctor gently feels the scrotum and groin to determine whether both testicles are present and in position. This physical examination is the primary diagnostic tool.
In some cases, a testicle may be “retractile,” meaning it moves up and down between the scrotum and groin due to a reflex. This is a normal finding that typically resolves by puberty and does not require surgery. A true undescended testicle, by contrast, cannot be manually guided into the scrotum or does not stay there once placed.
If a testicle cannot be felt during examination, imaging tests such as ultrasound or MRI may be used to locate it. However, these tests are not always reliable, especially for testicles inside the abdomen. In many cases, the definitive diagnosis is made during surgery.
What Treatment Options Are Available?
Treatment depends on the age of the child and the position of the testicle. The goal is always the same: to bring the testicle into the scrotum and secure it there.
Observation is appropriate for the first few months. Since many testicles descend spontaneously by 6 months of age, pediatricians typically recommend waiting and re-examining. No treatment is needed if descent occurs naturally.
Surgery, called orchiopexy, is the standard treatment for persistent cryptorchidism. The procedure moves the testicle into the scrotum and stitches it in place. It is usually performed between 6 and 18 months of age. Surgery is highly successful, with success rates above 90 percent when the testicle is in the groin.
The timing of surgery matters. Earlier surgery is associated with better long-term outcomes for fertility and potentially lower cancer risk. This is why pediatric urologists now recommend surgery by 18 months rather than waiting until school age, which was common practice in the past.
Hormone therapy using human chorionic gonadotropin (hCG) or gonadotropin-releasing hormone has been tried as a non-surgical alternative. Some studies show these hormones can stimulate descent in a minority of cases, but the overall success rates are low compared to surgery. Hormone therapy is not currently recommended as a first-line treatment by most pediatric urology guidelines.
What Happens After Treatment?
After successful surgery, most boys have no further problems related to the undescended testicle. The testicle remains in the scrotum and functions normally in most cases. Regular follow-up examinations ensure the testicle stays in position and grows appropriately through childhood and puberty.
Boys who had surgery should be taught testicular self-examination when they reach adolescence. This is not because their risk is dramatically high, but because their baseline risk is elevated compared to the general population. Knowing what is normal helps them notice any changes early.
Fertility outcomes after surgery are generally good, especially when the surgery was performed early and only one testicle was affected. Men who had bilateral cryptorchidism should be aware that their fertility may be reduced and can consider having their semen analyzed if they have concerns about starting a family. Most men with a history of unilateral cryptorchidism achieve normal fertility.
Can Cryptorchidism Be Prevented?
There is no reliable way to prevent cryptorchidism. Because the leading cause is prematurity, the most meaningful preventive step is reducing the risk of premature birth through good prenatal care. Beyond that, the condition is not something parents cause or can avoid.
What parents can do is ensure early detection and timely treatment. This means attending newborn examinations, following up on any concerns a pediatrician raises, and not delaying surgery if it is recommended. Early treatment is the single most important factor in reducing long-term risks.
Frequently Asked Questions
At what age should undescended testicle surgery be done?
Surgery is typically recommended between 6 and 18 months of age. Waiting past 18 months increases the risk of fertility problems later in life.
Can an undescended testicle cause infertility?
Yes, it can. The risk is higher when both testicles are undescended and when surgery is delayed beyond 18 months.
Is undescended testicle an emergency?
No, it is not an emergency in a newborn. It becomes urgent if the testicle suddenly becomes painful, swollen, or discolored, which may indicate torsion requiring immediate medical attention.
Will an undescended testicle fix itself?
Many do descend on their own during the first 3 to 6 months of life. If a testicle has not descended by 6 months, spontaneous descent is unlikely and treatment is needed.
