Host: It seems today sometimes girls, start to get a little pubic hair and nipples get budded and the kids may be seven or eight years old. Is that a problem? Could a girl get a period at a very young age, is that a problem?

Guest: A colleague of mine recently published a paper, that spoke to the fact that children tend to be entering puberty earlier today, than they have in past decades.

Host: What is the normal age for a girl for puberty?

Guest: What we have defined as normal and of course it's important to understand that definitions like this are arbitrary. We must pick a certain age, below which we would consider development to be early. However, that is not synonymous with disease. For even if the child begins to develop early, it's important to realize that most, if not the majority will in fact be a normal variation. With that said, the defining times for the earliest onset of development in girls is age eight and that includes that the development of pubic hair or breast and in boys age nine, the development of pubic hair and testicular enlargement.

On the other hand or on the late side we would consider the absence of any developments at the age of 12 or 13 in a girl and 13 or 14 in a boy to be considered abnormal. Despite the fact, that many of us have observed the early onset of pubic hair and body odor in many children as young as three, four and five years of age. The first age of the period, what is called menarche, seems to be quite stable for the last three thousand years at approximately 12.25 years. So even though, we are beginning to see some of the signs of puberty occurring earlier than we have used to see them, we are not seeing the actual change in the date of first period. Some of the reasons behind this may include excess exposure to fat in the diet, excess body weight, and excess risk of developing diabetes, in children where we see this kind of development.

So it may be that these signs although associate with puberty, really aren't true puberty but rather signs if you will of potential risk of the development of problems like diabetes and early heart disease later on in life.

Host: The girl does reach her first period, when does the height stops as levels off how soon?

Guest: Typically girls experience a growth spurt early, in the pubertal process. They experience breast development and that usually coincides with a spurt in growth, which contributes approximately 10% to 15% of final height to that child. Typically girls will experience period fairly late in puberty and at that time they are almost at their final adult height. It's quite possible that a child after experiencing their first period may grow an inch to an inch and half, but essentially the growth is complete by the time the first period happens.

In boys, however, they tend to go through most of their pubertal changes prior to their growth spurt and that their growth spurt occurs fairly late in the pubertal process.

Host: A very prominent question to pediatricians, they get a brand new little baby girl and they see blood coming from the girl's vagina. Does that mean a girl is going to have the period?

Guest: This phenomenon of a little bit of bleeding from a newborn's vagina is quite common and really has to do with a withdrawal of estrogen or female hormone, that the baby is exposed to while in the mother's uterus. That uterus is a rich environment filled with circulating hormones and when the baby is abruptly withdrawn from the mother's environment, the exposure to estrogen is also abruptly withdrawn and there may be a build up a little inside the baby's uterus, which is ultimately shed when there is that bleeding that occurs shortly after birth.

Host: We are also sometimes -- a baby boy or girl, there is a little bit of formation of the breast, little budding and sometimes there is a little whitish discharge. What causes that?

Guest: Quite commonly, in about 65% to 80% of newborn girls in particular, there will be the development of breast tissue between the ages of six months and approximately two-and-a-half years. We typically see about two to three children per week, who come in with that same complaint. It's important that families are reassured and in the absence of any real changes in the body or in the nipple consistent with true estrogen action on the body as we would see in early puberty, this represents a little mini puberty that normally goes girls through, that if you will primes and test the system out for later on in the years when a child will in fact go through the true puberty. We observe these children, we rarely get laboratory testing. We will see child back in three to four months and if there is no significant change, typically this tissue will regress, if not completely, mostly and parents will be reassured of the same.

Host: Thank you very much.