If you have a daughter, you're probably hoping she'll stay your "little girl" for a while. So you might be dismayed if her breasts start to develop at a young age. Breast development is normally the earliest sign of puberty, but can occur many years before other signs. Talk to your pediatrician if you notice early signs of premature breast development, but rest assured that it probably isn't a sign of a health disorder.
Normal Breast Development
Breast development in the form of small nickel-sized lumps under the nipple is the first sign of puberty, normally occurring around age 9 to 10, according to the American Academy of Pediatrics. Breast development in girls younger than age 6 for black girls and before age 7 in white girls is considered premature, the AAP explains. A study reported in the August 2010 issue of "Pediatrics" found that 10 percent of white girls, 23 percent of black girls and 15 percent of Hispanic girls experienced stage 2 breast development by age 7. Breast development in girls now occurs about one year earlier than it did a few decades ago, WebMD reports.
Why Premature Breast Development Occurs
Premature breast development can occur in girls just a few years old. In most cases, the cause is unknown. Overweight and obesity appears to play a role, but the onset of breast development has gotten younger even in countries where obesity is less prevalent in the United States, the WebMD website reports. Overweight girls produce more leptin, which can trigger the onset of puberty, endocrinologist Glenn D. Braunstein of Cedars-Sinai states in a February 2013 article on "The Huffington Post." Girls with early breast development don't generally have higher levels of estrogen, the main female hormone, according to pediatrician Michael Kappy of the Children's Hospital; they might be temporarily more sensitive to normal estrogen levels.
What It Means
While breast development starts at younger ages than it did a decade or two ago, menstruation normally doesn't start before age 12 or 13, only a few months earlier than it did several decades ago, according to Braunstein. Girls who experience early breast development don't normally experience early puberty and premature breast development generally doesn't progress significantly. In most cases, premature breast development isn't associated with serious health issues.
When to Seek Treatment
If your little girl shows early signs of breast development, it's important that her pediatrician is aware and follows her closely for signs of complications such as precocious puberty caused by endocrine disorders or a brain tumor. As long as the child is growing normally, around 2 inches each year and doesn't show other signs of early puberty, such as acne, pubic or axilla hair or menses, she's unlikely to have any serious health problem.