Overview

A micropenis is a penis that is smaller than normal. The normal length of a newborn boy's penis is 2.8 to 4.2 centimeters (1.1 to 1.6 inches). The measurement around a newborn boy's penis (the circumference) is normally 0.9 to 1.3 cm (0.35 to 0.5 inches). The penis is measured by carefully stretching it. The penis is measured from the tip to the base. A penis length of less than 1.9 cm (0.75 inches) is considered micropenis.

Causes

Micropenis can happen on its own. But it usually happens along with other disorders. Micropenis can happen if a child has a hormone disorder that causes an abnormal level of the hormones involved in the growth of the sexual organs. This can include problems with the pituitary gland or the hypothalamus.

Symptoms

The most common sign of a micropenis is penis size in a baby that is less than 1.9 cm when stretched gently.

The symptoms of micropenis can seem like other health conditions. Make sure your child sees his healthcare provider for a diagnosis.

Diagnosis

The healthcare provider will ask about your child’s symptoms and health history. He or she may also ask about your family’s health history. He or she will give your child a physical exam. The physical exam may include carefully measuring your child’s penis. Your child may also have blood tests or other testing to check for a hormone disorder.

Treatment

Treatment will depend on your child’s symptoms, age, and general health. It will also depend on how severe the condition is.

Your child may be referred to specialists. These may include:

  • Pediatric urologist. This is a healthcare provider who focuses on problems with the urinary tract and the male genitals in children.
  • Pediatric endocrinologist. This is a healthcare provider who focuses on problems with hormones in children.

Hormone therapy may be used for some children. These can help to cause penile growth. In some cases, your child may need surgery. Talk with your child’s healthcare providers about the risks, benefits, and possible side effects of all treatments.

Complications

In some cases, a man with micropenis may have low sperm count. This can result in infertility or decreased fertility.

When to Call a Healthcare Provider

Call the healthcare provider if your child has:

  • Symptoms that don’t get better, or get worse
  • New symptoms

Key Points

  • A micropenis is a penis that is smaller than normal. A penis length of less than 1.9 cm (0.75 inches) for a newborn boy is considered micropenis.
  • Micropenis can happen on its own. But it usually happens along with other disorders.
  • This condition can occur if a child has a hormone disorder that causes an abnormal level of the hormones involved in the growth of the sexual organs. This can include problems with the pituitary gland or the hypothalamus.
  • Hormone therapy may be used to treat some children. This can help to cause penile growth. Sometimes surgery may be an option.
  • In some cases, a man with micropenis may have low sperm count. This can result in infertility or decreased fertility.

Next Steps

Tips to help you get the most from a visit to your child’s healthcare provider:

  • Know the reason for the visit and what you want to happen.
  • Before your visit, write down questions you want answered.
  • At the visit, write down the name of a new diagnosis, and any new medicines, treatments, or tests. Also write down any new instructions your provider gives you for your child.
  • Know why a new medicine or treatment is prescribed and how it will help your child. Also know what the side effects are.
  • Ask if your child’s condition can be treated in other ways.
  • Know why a test or procedure is recommended and what the results could mean.
  • Know what to expect if your child does not take the medicine or have the test or procedure.
  • If your child has a follow-up appointment, write down the date, time, and purpose for that visit.
  • Know how you can contact your child’s provider after office hours. This is important if your child becomes ill and you have questions or need advice.