A clinical follow-up study of premature thelarche in infants under the age of two

Result 1.Hospital-based prevalence in infants under the age of 2 years in 2009, 2010 and 2011 is 0.26‰, 0.40‰, 0.39‰ relatively. On average it’s 0.35‰. Period from July to September in every year is the peak time of doctor visiting. 2. Most (99.8%)of infants with premature thelarche are manifested as isolated premature thelarche, while only 0.2% are represented as peripheral precocious puberty. 3. Among the patients under the age of 2 years with isolated premature thelarche 89.5% of them get a regression between the age of 2 and 3 years( The average of regression age is 17±5.8 months), 10.5% of them do not make recovery by the age of 3 years and even some (0.4%) turn into central precocious puberty(CPP). 4. The two influencing factors of breast regression are breast size by the first time of doctor visiting and whether basal estrogen is high or not.