While puberty can begin at different ages that vary by ethnicity, the current limit for diagnosing the process as premature is around the age of 8 years.
However, it can be difficult to get older if early is too early, especially as girls are entering puberty at an increasingly younger age.
Katherine Kutney, MD, a pediatric endocrinologist at Rainbow Babies and Children’s Hospital in Cleveland, Ohio. said thelarche, or breast development during puberty, is considered to occur prematurely when a girl reaches Tanner Stage 21 — with a palpable breast bud below the areola — at age 8. Breast development without a breast bud is usually just a collection of fatty tissue and not a sign of true puberty.
Reaching Tanner Stage 2, with a palpable breast bud intact, at age 8 may be a sign of early thelarche, Kutney noted, this isn’t always the case.
Parents are sometimes alarmed by the development of breast tissue in girls during childhood, but this is normal, Kutney explained. Exposure to maternal estrogen in utero induces a physiological mini-puberty that can last from birth to approximately 4 months of age. The mother’s hormones temporarily activate the hypothalamic-pituitary-gonadal (HPG) axis – which typically begins the process of puberty. In infants, this corrects after a few months as the mother’s hormones disappear. Breast tissue can persist for the first 2 years of a girl’s life, but breast development that occurs without other signs of puberty, such as pubic hair growth spurts, is considered benign, Kutney said.
Signs of benign premature thelarche include:
Breast development that does not progress beyond Tanner Stage 3 Breast development that occurs in addition to a normal growth rate for the child’s age Breast development that occurs at normal or near-normal bone age
Early breast development and other signs of early puberty are one of the top reasons for referrals to pediatric endocrinology specialists, but research suggests that early or precocious puberty is usually considered a problem only when breast development progresses over a 4 to 6 year period. month period next to a growth spurt
“My recommendation would be to refer any girl with thelarche that persists after age 2 or before age 8 to pediatric endocrinology for evaluation,” suggested Kutney.
Some reports have suggested changing the guidelines for diagnosing thelarche as girls are entering puberty earlier.3 However, a 2016 clinical report from the American Academy of Pediatrics suggests using the traditional guidelines because of concerns that lowering the rate of thelarche could lead to a higher level of puberty. typical age for thelarche can lead to missed diagnoses of endocrine disorders
Emmanuel M, Bokor BR. Tanner stages. Stat Pearls Publishing. 2021. Kaplowitz P, Bloch C. Section on Endocrinology, American Academy of Pediatrics. evaluation and referral of children with signs of early puberty. Pediatrics. 2016;137(1). doi: 10.1542/peds.2015-3732.Eckert-Lind C, Busch AS, Petersen JH, et al. Global secular trends in age at puberty onset assessed by breast development in girls: a systematic review and meta-analysis . JAMA Pediatrician. 2020;174(4):e195881. doi:10.1001/jamapediatrics.2019.5881