What is micropenis?

Micropenis is defined as a normally structured penis that is below the normal size range by more than 2 standard deviations. Normally, the length of a newborn boy’s penis is between 2.8 to 4.2 centimeters (1.1 to 1.6 inches) with a circumference of 0.9 to 1.3 centimeters (0.35 to 0.5 inches). This measurement is taken by carefully stretching the penis and measuring from the tip of the penis to the base of the penis (at the bone and not at the level of the skin). A penis length of less than 1.9 centimeters (0.75 inches) is usually considered micropenis.

What causes micropenis?

Micropenis can occur alone, but usually occurs in combination with other disorders. Hormone disorders that cause an abnormal level of hormones which are involved in development of the sexual organs may be seen in combination with micropenis. This can involve the pituitary gland or the hypothalamus.

What are the symptoms of micropenis?

Typically, a micropenis is an infant penis size that is less than 1.9 centimeters when stretched gently and measured from the base at the bone. Measurements taken at the level of the skin can cause false readings as the child’s fat pad will cover some of his penis length. Micropenis may or may not be seen in conjunction with other disorders.

How is micropenis diagnosed?

Diagnosis is usually made by physical examination. Children may then be referred to several specialists including pediatric urologist at the CHOC Urology Center and a pediatric endocrinologist (a doctor who specializes in hormones).

What is the treatment for micropenis?

Specific treatment for micropenis will be determined by your child’s doctor based on:

  • The child’s age, overall health and medical history.
  • The extent of the condition.
  • The child’s tolerance for specific medications, procedures or therapies.
  • Expectations for the course of the condition.
  • The family’s opinion or preference.

Hormone therapy may be indicated for some children to stimulate penile growth.