Enlarged breast tissue is very common at birth in both sexes. It usually resolves by six months of age . 

Premature Thelarche

1. A benign condition that usually presents before two years of age with breast tissue development. It may be bilateral or effect only one breast. There are no other signs of estrogen effect including internal genitalia changes, uterine enlargement, growth acceleration or advancement of bone age. 
2. The breast enlargement may last for 3-5 years and regression begins earlier in girls with the onset prior to 2 years of age. There is no association with delay of menarche and abnormal breast development. Follow-up studies have not demonstrated any reproductive problems. On ultrasound of the ovaries, some studies have shown a small cyst in normal sized ovaries. 
3. LHRH and FSH are higher than in normal girls but not as as high as those with true precocious puberty. Bone age is also normal.
4. Treatment is reassurance and careful observation to make sure that the thelarche is not the first manifestation of precocious puberty. In one study, 6% of premature thelarche represented the earliest sign of true precocious puberty.

1. Adrenarche is the presence of pubic hair before 8 years of age in girls and 9 years of age in boys. It may be associated with the development of axillary hair and adult axillary odor. It is a benign condition that requires no treatment. 
2. There is premature production of increased amounts of dehydroepiandosterone in the adrenal. 
3. Higher incidence in African American females. 
4. Will require investigation if there is associated growth acceleration with advancing bone age and clitoral or penal enlargement
5. Some endocrinologist suggest all children be evaluated.
6. Children should be followed carefully to make sure that other secondary traits don't develop and that there is no abnormal growth acceleration. 

1. Pediatrics in Review. Premature Thelarche. February 1987.
2. Root AW. Precocious Puberty. Pediatrics in Review. 2000; 21:10-19.
3. Nebesio T. and Eugster E.  Pubic Hair in Infancy, Endocrinopathy or Enigma?  Pediatrics March 2006