Dr. Greene's Answer
“It’s a boy!”
When we first glimpse our children in the delivery room, their sex is one of the immediate things we notice. It’s also one of the first things we report to family and friends. In the last generation, many of us have seen evidence of our children’s sex on ultrasound even before they were born, but still at the birth, we look to see.
How disconcerting to parents when a boy’s penis seems to disappear, either at birth or shortly thereafter. The good news is that the outlook is bright. Sometimes surgery is needed, sometimes medical treatments, and often nothing at all.
When a penis appears absent or too small, we call the condition inconspicuous penis (Walsh: Campbell’s Urology, 7th ed., W. B. Saunders Company, 1998). I’ve seen this in a great many boys. Several very different situations are lumped into this category. I will describe webbed penis, concealed penis, trapped penis, micropenis, and absent penis.
A webbed penis is a normal-sized penis where the skin of the scrotal sack extends part way up the shaft of the penis. Boys can be born this way, or the condition can result from an over-exuberant circumcision where adhesions form between the scrotal skin and the penile skin. Webbed penis usually causes no problems (unless a routine circumcision is later performed). It is unlikely to get better as the child grows. Results with surgery, however, are excellent. (Casale AJ – Concealed penis in childhood: a spectrum of etiology and treatment. J Urol – 1999 Sep; 162(3 Pt 2): 1165-8).
A concealed penis is a normal-sized penis that lays hidden in the pubic fat pad. This condition is also called buried penis or hidden penis. Some children are born this way, and for some it happens after circumcision. It is common in infants and toddlers, and occasionally seen in older children and obese adolescents. If the penis can be easily exposed by gently pulling on it or by pressing down on the surrounding fat pad, then the situation will usually correct itself over time. Sometimes surgery is needed for concealed penis. Either way, “social, urinary and erection” results are excellent.
A trapped penis is a normal-sized penis that is partially stuck in the pubic fat pad. Children are not born with trapped penis; circumcision causes it. Routine circumcision of a webbed penis or circumcision when there is significant scrotal swelling (from a hydrocele or hernia) can lead to trapped penis. Scarring or adhesions trap the recessed penis in the fat pad. This condition can predispose children to urinary tract infections or urinary retention. Surgery is usually wise.
All of the above conditions have a penis of normal size. In determining size, the “stretched penile length” is far more important than the “relaxed length.” To evaluate penis size, stretch the penis gently and measure from the bone at the base all the way to the tip. Be sure to depress the surrounding fat pad to get all the way to the base. Here are the normal values:
Average Penis Size — Stretched Penile Length
(Adapted from Feldman KW, Smith DW. Journal of Pediatrics. 1975; 86:395):
Normal: Mean +/- 1 SD (inches)
Abnormal: Mean – 2.5 SD (inches)
1.5 +/- 0.3
1.7 +/- 0.3
1.9 +/- 0.3
2.0 +/- 0.4
2.2 +/- 0.4
2.2 +/- 0.4
2.4 +/- 0.4
2.5 +/- 0.4
5.2 +/- 0.6
Micropenis is a penis that is more than 2.5 standard deviations below the average size for age. In a newborn, a stretched penile length less than ¾ inch (1.9 cm) is micropenis.
Micropenis is a hormonal problem that takes place sometime after 14 weeks gestation when the penis has already formed. Hormone levels need to be checked. A boy’s chromosomes should also be checked to see if there is an underlying genetic syndrome. An MRI may be needed to look at the hormone secreting glands. If the penis grows when a 3 month-trial of testosterone is given, the outlook is good for normal adult penis size and function.
If micropenis does not respond to testosterone stimulation, the difficult question of re-assigning gender arises. This decision has been made even more difficult by conflicting and changing recommendations of experts in the field. (Van Wyk JJ, Calikoglu AS, Should boys with micropenis be reared as girls? Journal of Pediatrics, 1999; 134(5)) At one time, gender re-assignment was the routine choice, even though it involves castration, surgical reconstruction, estrogen supplements, and huge emotional issues for the child and family. (Many people based their opinions on the case of a baby boy whose penis was accidentally amputated during circumcision. When he was 22 months old, he was castrated and reassigned a female sex. He had surgery to make his genitals appear female. He was raised as a girl. At puberty, he was given estrogens to promote breast growth. Reports said that he had a very good adjustment to the female sex, but it later became clear that from an early age he had rejected the idea that he was a girl. During his teen years, he insisted on switching back to living as a man. He later married as a man. (Diamond M, Sigmundson HK. Sex reassignment at birth. Long-term review and clinical implications. Arch Pediatr Adolesc Med 1997;151:298-304.) Recent long-term studies of micropenis, though, have found that even if the penis remains small, most boys-raised-as-boys end up as sexually active, heterosexual males who stand to urinate, have a strong male identity, normal erectile function, and who enjoy sex. (Reilly JM, Woodhouse CR. Small penis and the male sexual role. J Urol 1989;142:569-71.) Their partners also report sexual satisfaction. (van Seters AP, Slob AK. Mutually gratifying heterosexual relationship with micropenis of husband. J Sex Marital Ther 1988;14:98-107.) Teasing from peers can be a real problem, though. A penile prosthesis may help.
Adults who have themselves had intersex issues argue strongly against reassignment before the child is old enough to choose. (Van Wyk JJ, Calikoglu AS, Should boys with micropenis be reared as girls? Journal of Pediatrics, May 1999. 134(5).) Their opinion should be listened to carefully.
Penile agenesis or absent penis, is very rare, occurring in fewer than 1 in 20 million boys. (Gillenwater JW. Adult and Pediatric Urology. Mosby Year Book. 1991.) The scrotum and testicles usually form normally, but the penis doesn’t form at all. A team including a geneticist, endocrinologist, urologist, pediatrician, and mental health experts should be involved.
Many times, I have looked into parents’ worried faces over their son’s inconspicuous penis. When a boy has an inconspicuous penis, the parents’ concerns are quite understandable. The penis should be promptly examined and measured, and the parents should be clearly told whether it is normally formed and of normal size. Whenever any question remains, a pediatric urologist is the best person to evaluate the penis and recommend a plan. Consulting a urologist is all the more appropriate when new concerns arise as the boy grows.