Penile growth in response to hormone treatment in children with micropenis

Micropenis is defined as a stretched penile length 2.5 standard deviations less than the mean for age without the presence of any other penile anomalies, such as hypospadias. The term refers to a specific disorder that has a known set of causative factors and defined treatment modalities. The purpose of this study was to determine the effect of hormonal therapy on the gonadal response and penile growth in children who presented with micropenis.

Children (<18 years) who met the criteria for micropenis were included in this study. Children more than 11 years old were treated using a standard protocol of 1,500 to 2,000 IU human chorionic gonadotrophin administrated intramuscularly, once per week, for 6 weeks. Children less than 11 years old were treated with parenteral testosterone enanthate 25 mg once a month for 3 months. Response was evaluated in terms of change in testosterone levels and size of penis.

Serum testosterone levels at baseline and after 8 weeks of hormonal treatment were <20 and 449.4 ng/mL, respectively (P < 0.0001) in all children more than 11 years old. Stretched penile length after hormonal treatment increased from 15.54 to 37.18 mm in children less than 11 years old and from 26.42 to 64.28 mm in children more than 11 years old (P < 0.001).

Management of isolated micropenis revolves around testosterone (direct administration or encouraging the patient's body to make its own), and results with respect to increase in penile length are promising.