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Kryptorchidism (Undescended Testicle)

Overview

Kryptorchidism, commonly called an undescended testicle, is a condition in which one or both testes fail to move (descend) into the scrotum before birth. The testes normally develop inside the abdomen and travel down the inguinal canal to the scrotum during the third trimester of pregnancy. When this journey is incomplete, the testicle remains in the abdomen, the inguinal canal, or just above the scrotum.

• Who it affects: Primarily infants and young boys. In rare cases, an adult may discover an undescended testicle that was missed at birth.
• Prevalence: Approximately 3–4% of full‑term newborn males have at least one undescended testicle. The rate rises to 30% in premature infants (<37 weeks gestation) and drops to less than 1% after the first year of life when spontaneous descent can still occur.<sup>1</sup>
• Why it matters: If left untreated, kryptorchidism increases the risk of infertility, testicular torsion, and testicular cancer later in life.

Symptoms

Many infants with an undescended testicle have no obvious symptoms; the condition is often discovered during a routine newborn exam. When symptoms do occur, they may include:

• Absent or inadequately sized testicle in the scrotum – the scrotal sac feels empty on one side.
• High‑riding testicle – the testicle can be felt in the groin (inguinal canal) or just above the scrotum.
• Pain or discomfort – especially if the testicle becomes torsed (twisted) or incarcerated.
• Swelling or a lump in the groin or abdomen.
• Inguinal hernia – a bulge in the groin caused by the same developmental pathway; up to 30% of boys with undescended testes also have a hernia.<sup>2</sup>
• Fertility concerns later in life – reduced sperm count or quality, often recognized during adolescence or adulthood.

Because most newborns cannot verbalize pain, careful physical examination is essential.

Causes and Risk Factors

Primary Causes

The exact mechanism is not always clear, but several developmental factors can interrupt testicular descent:

• Hormonal disturbances: Low levels of testosterone or insufficient production of insulin‑like factor 3 (INSL3) hinder the hormonal “pull” that moves the testis.
• Genetic mutations: Mutations in genes such as INSL3, RXFP2, and those involved in androgen pathways have been linked to familial cases.
• Structural anomalies: Abnormalities of the gubernaculum (the fibrous cord that guides descent) or the inguinal canal can physically block the pathway.

Risk Factors

• Prematurity: The most significant risk factor; the earlier the birth, the higher the likelihood of non‑descent.
• Low birth weight: Often accompanies prematurity and reflects overall developmental delay.
• Maternal smoking or alcohol use during pregnancy – toxic exposures can affect fetal hormone production.
• Family history: A brother or father with a history of undescended testes increases risk two‑fold.
• Congenital syndromes: Conditions such as Prader‑Willi, William‑Beuren, and Klinefelter may present with cryptorchidism.

Diagnosis

Diagnosis is primarily clinical, performed by a pediatrician, urologist, or pediatric surgeon.

Physical Examination

1. Inspection of the scrotum for size and symmetry.
2. Palpation of the inguinal region to feel for a testicle that may be located in the canal.
3. Assessment for an associated inguinal hernia.

Imaging Studies (when the testicle is non‑palpable)

• Ultrasound: Often first‑line because it is non‑invasive; can locate a testicle in the abdomen or groin.
• Magnetic Resonance Imaging (MRI): Offers higher resolution for deep abdominal testes but is used less frequently due to cost.
• Laparoscopy (diagnostic): Provides direct visualization and can be combined with treatment in the same procedure.

Laboratory Tests

Routine labs are not required for diagnosis, but a baseline hormone panel (LH, FSH, testosterone) may be ordered if there is suspicion of endocrine dysfunction or before surgery in older children.

Treatment Options

Timely intervention is crucial. The American Academy of Pediatrics (AAP) recommends surgical correction (orchiopexy) before 12–18 months of age.

Non‑Surgical Management

• Observation: For preterm infants, doctors may wait until 6 months corrected age because up to 70% of testes descend spontaneously by then.<sup>3</sup>
• Hormonal therapy: Human chorionic gonadotropin (hCG) or gonadotropin‑releasing hormone (GnRH) can stimulate descent in some cases, but success rates are modest (30–40%) and side‑effects (e.g., premature virilization) limit routine use.

Surgical Treatment – Orchiopexy

1. Open orchiopexy: A small incision in the groin, mobilization of the testicle, and fixation to the scrotal wall.
2. Laparoscopic orchiopexy: Minimally invasive; useful for high intra‑abdominal testes.
3. Fowler‑Stephens procedure: For testes that cannot be brought down without cutting the spermatic vessels; the testicle is temporarily relocated to the thigh and later moved to the scrotum.

Success rates exceed 95% when performed by experienced pediatric surgeons, with low complication rates.

Post‑operative Care

• Scrotal support (jockstrap) for 1–2 weeks.
• Pain control with acetaminophen or ibuprofen.
• Follow‑up ultrasound at 6–12 months to confirm position and blood flow.

Living with Kryptorchidism (Undescended Testicle)

After treatment, most boys lead normal lives. Ongoing management includes:

• Self‑examination: Teach the child (around puberty) to gently feel each testicle for size, position, and any lumps.
• Regular pediatric urology visits: At least annually through adolescence to monitor growth and hormonal status.
• Fertility counseling: If both testes were undescended or orchiopexy was delayed, a semen analysis may be recommended during late teens.
• Psychosocial support: Some boys experience anxiety about body image; reassure them that, after successful orchiopexy, the scrotum looks typical.
• Protection during sports: Use an athletic cup to protect the repaired testicle from trauma.

Prevention

Because many causes are congenital, primary prevention is limited. However, these measures can reduce risk:

• Maternal smoking cessation and avoidance of alcohol/drugs during pregnancy.
• Optimal prenatal care to decrease premature birth rates.
• Management of maternal health conditions (e.g., diabetes) that may affect fetal hormone production.
• Genetic counseling for families with a history of cryptorchidism.

Complications

If undescended testicles are not corrected, several long‑term problems may arise:

• Infertility: The higher temperature of the abdomen impairs spermatogenesis. Up to 40% of men with bilateral cryptorchidism are infertile, and 10–15% with unilateral disease have reduced sperm counts.<sup>4</sup>
• Testicular cancer: Risk is 3–8 times higher than in the general male population, most commonly seminoma or non‑seminomatous germ cell tumors. Cancer can develop even after successful orchiopexy, so lifelong testicular surveillance is advised.
• Testicular torsion: Malpositioned testes are more prone to twisting, causing acute pain and loss of blood flow.
• Inguinal hernia or hydrocele: Persistent patent processus vaginalis may allow abdominal contents to protrude.
• Psychological impact: Concerns about body image, sexuality, or fertility can affect self‑esteem.

When to Seek Emergency Care

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Key Take‑aways

• Kryptorchidism affects 3–4% of full‑term newborn males and up to 30% of preterm infants.
• Early physical exam and, when needed, imaging are essential for diagnosis.
• Orchiopexy before 12–18 months dramatically reduces infertility and cancer risk.
• Long‑term follow‑up includes self‑examination, periodic urologist visits, and fertility counseling.
• Seek emergency care for acute pain, swelling, or signs of torsion.

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