Thelarche is part of normal maturation in females or it can occasionally occur early or prematurely and be considered an abnormal finding. Like menarche, the first period, thelarche represents another first. This is when the breasts first begin to develop and a small breast bump, bud, or lump because perceivable right underneath the nipple.
Normal thelarche may range in time of occurrence. Some define this as being normal when it occurs any time after the age of six, or others suggest a better average age is about eight. Like menarche, there can be vast range in when breast buds first occur. They also don’t always occur simultaneously and there could be some difference in size of breasts, or months between development of one breast and the other.
Though first periods are often thought of as a time a girl “becomes a woman,” thelarche illustrates the gradual nature of puberty. Signs of developing breasts usually occur before the first period and they represent an increase in the female hormone, estrogen or estradiol, which will ultimately lead to ovulation and menstruation. It is not uncommon for there to be more than a year between thelarche and menarche.
Under some circumstances, breast bud development occurs at a much earlier time. Sometimes girls between the age of one and three might have noted development of breast buds. This is usually not accompanied by any other symptoms of sexual development, and it would be extremely unusual for the breast to continue to enlarge to average woman size. Significant enlargement of the breasts won’t take place until real puberty occurs. Often the condition goes away within a few years time and a clear cause cannot be found.
There are some premature thelarche causes that do need to be considered. One could be exposure to hormones from another source, such as ingestion of birth control pills or coming in contact with estrogen creams. Sometimes there is evidence of other signs of puberty or elevated hormones that can suggest dysfunction with glands like the pituitary gland. Doctors will ordinarily test for any abnormalities of this sort and, as stated, the situation may simply resolve. Sometimes girls who have premature thelarche also have precocious puberty, beginning sexual maturation before they are eight.
In almost all instances thelarche occurs only in females. Yet, baby boys may occasionally have enlarged breasts too. This is generally caused by exposure to the mother’s hormones while in the womb. It is transient and suggests nothing about gender identity or normal male sexual maturation.