Undescended testes or cryptorchidism is defined as the incomplete descent of one or both testes and absence from the scrotum.

• 3.7% at birth and 1.0% at 3 months of age
• Most will have descended by 3 months if they are going to descend spontaneously

• True undescended testes — testes lie along the normal path of descent in the abdomen or inguinal region
• Ectopic testes — testes lie outside of the normal path of descent (e.g. femoral region, perineum, or penile shaft)
• Ascending testes — testes previously present in the scrotum and now not

• Most have no identifiable cause
• Rarely:
  • congenital hypogonadism
  • androgen insensitivity
  • ascending testes - significant proportion of late diagnoses

• Impaired fertility
• Increased risk of testicular cancer and testicular torsion if uncorrected

• If testis absent from the scrotum: sweep the groin region along the inguinal canal from lateral to medial. May be felt as a 'pop' under the examiner's fingers.
• If the testis is not present in the scrotum or inguinal region: check for an ectopic testis in the femoral, penile, and perineal regions
• Check for ambiguity of the external genitalia and for other genital abnormalities such as hypospadias
• Are there any syndromic features - associated syndromes e.g. Prader-Willi, Kallmann, or Laurence-Moon-Biedl?

Surgeons now prefer to undertake surgery earlier – preferably before 1 year.

• If bilateral undescended testes and/ or any signs of possible disorder of sexual development (e.g. ambiguous genitalia, or other associated genital abnormalities e.g. hypospadias) needs early senior review as may require urgent genetic/endocrine investigations - see below
• Unilateral:
  • Term – refer for surgical outpatient appointment
  • Preterm – there is a higher rate of spontaneous descent therefore refer if remain undescended at approximately 1 month post EDD. If discharged please highlight this for review at the first neonatal review clinic or GP 6 week check if no neonatal review planned in the discharge letter.

Record

• length of phallus (cm) -  should be at least 2.5cm
• position of urethral opening
• appearance and position of scrotum, and whether bifid
• any other midline opening

Presence or absence of 

• pigmentation
• other congenital abnormalities/dysmorphic features
• parental consanguinity

Birth weight centile

Any antenatal investigations e.g. amniocentesis

If any of above abnormal contact paediatric endocrine consultant

If external genitalia otherwise completely normal:

• Request pelvic USS for within a week: to view gonads and presence of any internal structures (uterus).

Baby to be reviewed on Day 4 weighed and re-examined (by middle-grade doctor or more senior).

• If either testis palpable - no investigations
• If no testes palpable: ACTH (on ICE), T, A4, 17OHP to screen for CAH; discuss karyotype for further information if testes do not descend spontaneously (not as a screen for CAH).

The person sending the ACTH is responsible for mechanism to review result (which should be within 1-2 days). If HIGH i.e. above normal range - urgent recall.

If ACTH within normal range (and weight loss also within the normal range) can await USS result. If abnormal i.e. uterus present, requires urgent action/recall.

Follow up plan needed for all:

Results of investigations will usually take 2-4 weeks (longer if karyotype)

• Review of ACTH: 1-2 days
• Review of USS: 1 week
• Review of T, A4, DHEAS, 17OHP: 2 weeks
• Review of karyotype: 6 weeks
• OPD for final results