Premature Thelarche

Premature Thelarche is a topic covered in the Select 5-Minute Pediatrics Topics.

To view the entire topic, please or purchase a subscription.

Medicine Central™ is a quick-consult mobile and web resource that includes diagnosis, treatment, medications, and follow-up information on over 700 diseases and disorders, providing fast answers—anytime, anywhere. Explore these free sample topics:

Medicine Central

-- The first section of this topic is shown below --



  • Breast development in girls <8 years of age without evidence of sexual hair development, vaginal mucosa estrogenization, linear growth acceleration, rapid bone maturation, adult body odor, or behavioral changes
  • Exaggerated thelarche, a variant of isolated breast development, occurs without axillary or pubic hair, but with some acceleration of growth and bone maturation, and increased uterine size.
  • Data suggests that African American girls may develop pubertal changes as early as 6 years of age and Caucasian girls as early as 7 years of age. However, caution should be used when evaluating children because signs of puberty at these younger ages may not be considered normal and may be due to pathologic conditions.


  • 60–85% of cases are noted between 6 months and 2 years of age.
  • There is no one identifiable group of girls who develops early thelarche.
  • Note: Breast enlargement in a male infant or young (prepubertal) boy should be concerning.


  • Transient increases in follicle-stimulating hormone levels causing follicular ovarian development
  • Low levels of estrogen secretion by normal follicular cysts
  • Increased sensitivity of breast tissue to low levels of estrogen
  • Delay in inhibition of the “minipuberty” of infancy
  • Exposure to exogenous estrogen (e.g., cosmetic and hair products, infant formulas containing soy, and xenoestrogens)

-- To view the remaining sections of this topic, please or purchase a subscription --