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Cryptorchidism – A Complete Medical Guide

Overview

Cryptorchidism, also called undescended testicle(s), is a congenital condition in which one or both testes fail to move (descend) into the scrotum before birth. In most cases the testes are located in the abdomen, the inguinal canal, or high in the groin. The condition is the most common genital abnormality in newborn boys.

• Who it affects: Nearly all cases occur in males; it is never seen in females.
• Prevalence: Approximately 1–4% of full‑term newborn boys are born with an undescended testicle. The rate rises to 10–30% in premature infants (<37 weeks gestation) because testicular descent normally completes during the third trimester.
• Age of resolution: Up to 70% of cases resolve spontaneously by 3–6 months of age, which is why many clinicians wait until after the first year before intervening.

Symptoms

Many infants with cryptorchidism have no obvious symptoms other than an absent testicle in the scrotum. However, several signs may alert parents or clinicians:

• Absent or asymmetrical testicle in the scrotum – The most reliable clue.
• Poorly developed scrotum – The scrotal sac may be small or have a smooth, “flat” feel on the affected side.
• Pain or tenderness – Rare in newborns but may appear if the undescended testis becomes torsed or incarcerated.
• Swelling or a palpable mass in the groin or abdomen – Indicates the testis is located higher up.
• Hormonal signs (older children) – Delayed puberty or lack of secondary sexual characteristics if both testes remain undescended.
• Infertility clues later in life – Low sperm count or abnormal semen analysis when the condition was untreated.

Causes and Risk Factors

Normal physiology of testicular descent

Testicular descent occurs in two phases:

1. Transabdominal phase (weeks 8–15): The testes move from the abdomen to the internal inguinal ring, driven mainly by insulin‑like factor 3 (INSL3) and the gubernaculum (a ligament‑like structure).
2. Inguinoscrotal phase (weeks 25–35): Testosterone and the genitofemoral nerve stimulate migration through the inguinal canal into the scrotum.

Factors that disrupt descent

• Premature birth: Early termination of pregnancy truncates the hormonal window needed for descent.
• Low birth weight (<2500 g): Associated with reduced hormonal activity.
• Genetic syndromes: Klinefelter syndrome (47,XXY), Turner syndrome, Noonan syndrome, and mutations in the INSL3 or RXFP2 genes.
• Maternal factors: Smoking, alcohol use, or exposure to endocrine‑disrupting chemicals (e.g., phthalates, pesticides) during pregnancy.
• Family history: A brother or father with cryptorchidism raises risk 2–3‑fold.
• Urogenital anomalies: Hypospadias, inguinal hernia, or other pelvic malformations often coexist.

Diagnosis

Diagnosis is primarily clinical but may be supplemented with imaging or lab tests when the testis is non‑palpable.

Physical examination

• Infants are examined in a warm room, with the scrotum gently pulled down to lower the cremasteric reflex.
• Palpation of the inguinal canal and abdomen determines if the testis is “retractile” (can be brought down but quickly retracts) versus truly undescended.

Imaging studies

• Ultrasound: Useful for locating a testis that is palpable in the inguinal region; limited for abdominal testes.
• Pediatric MRI: Highly sensitive for intra‑abdominal testes when ultrasound is inconclusive.
• Laparoscopy (diagnostic): Direct visualization; considered both diagnostic and therapeutic if the testis is not found by non‑invasive methods.

Laboratory tests

• Hormone levels (LH, FSH, inhibin B, testosterone) are rarely required but can help assess gonadal function in older children or adolescents.
• Genetic testing may be indicated when a syndrome is suspected.

Timing of evaluation

Guidelines from the CDC and American Academy of Pediatrics (AAP) recommend:

• Initial newborn exam at birth.
• Re‑examination at 1–3 months of age (corrected age for pre‑terms).
• If the testis remains undescended at 6 months, referral to a pediatric urologist or surgeon.

Treatment Options

Early treatment (before 12–18 months) improves fertility outcomes and reduces cancer risk.

Surgical correction – Orchiopexy

• Standard orchiopexy: A small incision in the groin or scrotum, mobilizing the testis and securing it within the scrotal sac.
• Laparoscopic orchiopexy: Preferred for intra‑abdominal testes; minimally invasive and allows excellent visualization.
• Success rates exceed 95% with low complication rates (<2% wound infection, <1% recurrence).
• Optimal timing: 6–12 months of age (ideally before 1 year).

Non‑surgical options

• Hormonal therapy: Human chorionic gonadotropin (hCG) or gonadotropin‑releasing hormone (GnRH) analogs have been studied to stimulate descent, but meta‑analyses show modest success (10‑20%) and potential side‑effects (pubertal acceleration, mood changes). Not routinely recommended as first‑line.
• Observation: In premature infants, a short period of watchful waiting (up to 6 months corrected age) is acceptable because many descend spontaneously.

Post‑operative care

• Scrotal support and mild analgesia for 24‑48 hours.
• Avoidance of vigorous activity for 2–4 weeks.
• Follow‑up ultrasound at 6–12 months to confirm testicular position and size.

Living with Cryptorchidism

Daily management for children and adolescents

• Self‑examination: Once the child reaches school age, teach monthly testicular self‑exam to detect any change in size or position.
• Clothing: Loose‑fitting underwear reduces pressure on the scrotum and may improve comfort after surgery.
• Sports: Protective athletic cups are advisable after orchiopexy during contact activities for the first 3 months.
• Psychosocial support: Some boys experience embarrassment about a “missing” testis; counseling or peer support groups can be beneficial.

Fertility monitoring

Annual semen analysis is recommended after puberty for those who had delayed or unilateral correction, especially if the opposite testis was also abnormal.

Long‑term follow‑up

• Annual physical exam with a pediatric urologist until age 18.
• Serum tumor markers (AFP, β‑hCG, LDH) are not routinely required but may be ordered if a testicular mass appears.

Prevention

Because cryptorchidism is largely congenital, complete prevention is impossible, yet certain measures can lower risk:

• Optimize maternal health: Avoid smoking, limit alcohol, and maintain a balanced diet rich in folate and iodine.
• Minimize exposure to endocrine disruptors: Use BPA‑free containers, avoid pesticides, and choose fragrance‑free personal care products.
• Prevent preterm birth: Adequate prenatal care, treatment of infections, and management of chronic conditions (e.g., hypertension, diabetes) reduce early delivery.

Complications

If cryptorchidism remains untreated, several serious sequelae may develop:

• Infertility: Undescended testes are exposed to higher intra‑abdominal temperatures, leading to reduced sperm production. Bilateral cases have up to a 90% risk of subfertility; unilateral cases carry a 20–30% risk.
• Testicular cancer: The risk of germ cell tumors is 3–8 times higher than in the general male population, especially when the condition persists beyond puberty. The absolute risk remains low (≈0.5% overall) but warrants lifelong surveillance.
• Testicular torsion: An undescended testis is more mobile, increasing the chance of twisting its blood supply—a surgical emergency.
• Inguinal hernia: Approximately 15–20% of boys with cryptorchidism develop a concurrent hernia due to a patent processus vaginalis.
• Psychological impact: Body image concerns and anxiety may affect self‑esteem during adolescence.

When to Seek Emergency Care

Key Take‑aways

Cryptorchidism is a common, usually correctable condition that, when treated early, carries an excellent prognosis for both fertility and cancer risk. Parents should ensure timely evaluation, follow recommended surgical timelines, and maintain regular follow‑up through adolescence. When in doubt, especially with acute pain or swelling, seek emergency medical attention.

References:

1. Mayo Clinic. Undescended testicle (cryptorchidism). Accessed June 2026.
2. American Academy of Pediatrics. Management of undescended testes. Pediatrics. 2006.
3. World Health Organization. Cryptorchidism. WHO Fact Sheet, 2022.
4. National Institutes of Health (NIH). Testicular Cancer and Undescended Testes. 2021.
5. Cleveland Clinic. Cryptorchidism. Updated 2024.

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