Age range (years)Breast growthPubic hair growthOther changesAge range (years)Testes growthPenis growthPubic hair growthOther changes
I0–15Pre-adolescentNonePre-adolescent0–15Pre-adolescent testes
(≤2.5 cm)
II8–15Breast budding (thelarche); areolar hyperplasia with small amount of breast tissueLong downy pubic hair near the labia, often appearing with breast budding or several weeks or months laterPeak growth velocity often occurs soon after stage II10–15Enlargement of testes; pigmentation of scrotal sacMinimal or no enlargementLong downy hair, often appearing several months after testicular growth; variable pattern noted with pubarcheNot applicable
III10–15Further enlargement of breast tissue and areola, with no separation of their contoursIncrease in amount and pigmentation of hairMenarche occurs in 2% of girls late in stage III1½–16.5Further enlargementSignificant enlargement, especially in diameterIncrease in amount; curlingNot applicable
IV10–17Separation of contours; areola and nipple form secondary mound above breasts tissueAdult in type but not in distributionMenarche occurs in most girls in stage IV, 1–3 years after thelarcheVariable: 12–17Further enlargementFurther enlargement, especially in diameterAdult in type but not in distributionDevelopment of axillary hair and some facial hair
V12.5–18Large breast with single contourAdult in distributionMenarche occurs in 10% of girls in stage V.13–18Adult in sizeAdult in sizeAdult in distribution (medial aspects of thighs; linea alba)Body hair continues to grow and muscles continue to increase in size for several months to years; 20% of boys reach peak growth velocity during this period

Source: Adapted from reference [218].


Cover of Antiretroviral Therapy for HIV Infection in Infants and Children: Towards Universal Access
Antiretroviral Therapy for HIV Infection in Infants and Children: Towards Universal Access: Recommendations for a Public Health Approach: 2010 Revision.
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