In a full-term male infant, micropenis can be described as a penis that measures less than which length?

• A. 1
• B. 2.5
• C. 0.5
• D. 5

Answer: (B)

Micropenis is defined by a stretched penile length that is clearly below what’s expected for the baby’s age. For a full-term newborn, the commonly used cutoff is a stretched penile length less than 2.5 cm. The measurement is done with the infant lying flat, gently pulling the penis to its maximum length, and measuring from the base (pubic skin) to the tip of the glans. Values under 2.5 cm suggest micropenis and warrant evaluation for possible hormonal or developmental issues that affected androgen exposure during formation. Normal variation can occur, but 2.5 cm is the key threshold.