From the Guidelines
Tanner stages in boys are a standardized scale used to assess physical development during puberty, consisting of five stages, which help healthcare providers assess normal development, identify early or delayed puberty, and guide appropriate interventions when needed 1.
Overview of Tanner Stages
The Tanner stages are a scale of physical development in children, defining physical measurements of development based on external primary and secondary sex characteristics, such as the size of the genitals, testicular volume, and the development of pubic hair 1.
Breakdown of Tanner Stages
The stages are as follows:
- Stage 1 represents pre-puberty with no visible changes.
- Stage 2 typically begins between ages 9-14, marked by testicular enlargement, scrotal reddening, and sparse pubic hair.
- Stage 3 occurs around ages 10-15, with continued testicular growth, penile lengthening, and darker, curlier pubic hair.
- Stage 4 happens around ages 11-16, showing further genital growth, darkening of the scrotum, adult-type pubic hair that hasn't spread to the thighs, and voice changes.
- Stage 5, usually reached between ages 14-18, represents adult development with full-sized genitalia and pubic hair extending to the thighs.
Importance of Monitoring Tanner Stages
Monitoring Tanner staging annually beginning at 10 years of age is crucial, especially in individuals who may be at risk of delayed puberty, such as those with cardio-facio-cutaneous syndrome 1.
Factors Influencing Tanner Stages
The progression through these stages varies widely among individuals, with genetics, nutrition, and overall health influencing timing 1.
Clinical Application
Regular pediatric check-ups allow for monitoring of this development to ensure it proceeds appropriately, and endocrine evaluation is appropriate if onset of puberty is delayed beyond age 12 to 13 years 1.
From the Research
Tanner Stages in Boys
The Tanner stages are a scale used to measure physical development in children, adolescents, and adults [ 2, 3,4,5,6 ].
- The stages define physical measurements of development based on external primary and secondary sex characteristics, such as the size of the breasts, genitals, testicular volume, and development of pubic hair [ 2, 3,4,5,6 ].
- Due to natural variation, individuals pass through the Tanner stages at different rates 6.
- In boys, the Tanner stages are used to measure genital (G) and pubic hair (PH) development [ 2, 3,6 ].
Genital Development Stages
The genital development stages in boys are as follows:
- Stage 1: Prepubertal
- Stage 2: Enlargement of the testicles
- Stage 3: Enlargement of the penis
- Stage 4: Further enlargement of the penis
- Stage 5: Adult size and shape are reached [ 2, 3,6 ].
Pubic Hair Development Stages
The pubic hair development stages in boys are as follows:
- Stage 1: Prepubertal
- Stage 2: Long, curly, or straight hair appears
- Stage 3: Hair becomes darker and coarser
- Stage 4: Hair becomes adult in quantity and type
- Stage 5: Adult in quantity and type, and distributed in the classic male pattern [ 2, 3,6 ].