The London Clinic provides a full breast care service for women who are worried about their breast health or who have developed breast cancer. View our Breast services. The London Clinic is fully committed to compliance with Data Protection and medical confidentiality guidelines. Please see our Privacy Notice for further details on how we use your personal data. Breast development starts in an unborn baby and is completed during puberty and pregnancy.

On average, it's about two years from the time a girl first starts to show any breast development to the time that she actually starts her periods. Since girls in the United States start their periods anywhere from 9 to 15 years of age, breast development starting as early as 7 years of age is normal. In general, a girl starts her period in a pattern similar to her mother; if Mom started early, her daughter is more likely to start early. This isn't an absolute rule, though. Factors such as nutrition overweight children can start sooner than they otherwise might, and underweight children may start later and illness can influence the onset of puberty. Keep in mind that, when you discuss body changes and puberty with young girls, your approach may need to be very different if you're talking to an 8-year-old rather than a year-old.

Breast development happens in certain stages during a woman's life: first before birth, again at puberty, and later during the childbearing years. This starts with a thickening in the chest area called the mammary ridge or milk line. By the time a baby girl is born, nipples and the beginnings of the milk-duct system have formed. The first thing to develop are lobes, or small subdivisions of breast tissue.

Both boys and girls have breast tissue. Normal breast development first appears shortly after birth, and then again at the beginning of puberty. The timing of breast development varies greatly from one person to another and in some girls may not occur until well into the teenage years. Here's an overview of some of the main breast abnormalities that can occur in children. Baby girls and boys will have a small breast bud that can be felt for a few weeks after they are born.