Is my son’s penis size normal?

Paediatric urologists frequently encounter concerned parents who worry about the size of their child’s penis. It’s a topic that can cause unnecessary stress, often because of misunderstandings about what is considered "normal." In this article, accomplished consultant paediatric urologist and paediatric and neonatal surgeon Miss Marie-Klaire Farrugia aims to address these concerns and provide some clarity for parents.

What is a normal penis size for children?

The size of a child’s penis can vary widely, depending on their age and stage of development. At birth, the average penis length is around 2.0 to 4.2 cm when flaccid. While these numbers give a rough guide, it’s important to remember that variations are perfectly natural. Indeed, the penis may appear larger during the first few months of life, due to a period of “mini-puberty”, when there is a significant increase in testosterone levels, peaking around 1–3 months of age, and leveling off around 6 months. Following this time, there is no testosterone production untli puberty, and therefore, the penis does not grow very much during childhood. This frequently raises parental concern.

Most children will experience significant growth as they enter puberty, usually between ages 9 and 14. By the end of puberty, the penis usually reaches its adult size, though the timing of this growth can vary greatly from child to child.

Circumcised penises may sometimes appear smaller. It is not uncommon for circumcised penises to “sit inside” the supra-pubic fat pad and appear “buried”, but this is of no concern, and will improve as the child grows. It is certainly not an indication for surgical intervention.

Could my child have micropenis?

Micropenis is a medical term referring to a penis that is smaller than 2 standard deviations below the average for age and stage of development. In simpler terms, it means the penis is much smaller than expected for the child’s age. For infants, a length below 1.9 cm when stretched may be indicative of micropenis.

It is important to note that micropenis is rare and usually detected at birth or early in infancy. If you suspect your child has an unusually small penis, it is essential to consult a healthcare professional. Paediatricians can measure and assess the child’s growth to determine if further investigation is necessary.

What causes micropenis?

Micropenis can be caused by hormonal imbalances that occur during pregnancy, particularly a lack of testosterone, which is the hormone responsible for male sexual development. Conditions affecting the pituitary gland, which controls hormone production, or the testicles may also play a role.

In some cases, micropenis can be associated with genetic conditions or disorders of sexual development, including severe hypospadias. That said, most children with micropenis have normal function, including normal hormone levels after birth and the ability to experience typical sexual development during puberty.

Should I be concerned about my child’s penis size?

In the vast majority of cases, penile size is appropriate for age, and there should be no cause for concern. However, if parents would prefer reassurance, an assessment by an experienced paediatric urologist would include an overview, full examination and measurement of stretched penile length with plotting on a penile growth chart, to ensure that all is as expected.

Are there treatments available for micropenis?

Treatment of a micropenis will depend on the underlying diagnosis/ condition, and may include hormonal treatment and/or surgery. Such rare cases will be managed in a multidisciplinary clinic setting and may involve a number of experts, in particular, a paediatric endocrinologist.

If you are a concerned parent and would like to book a consultation with Miss Farrugia, do not hesitate to do so by visiting her Top Doctors profile today.