“Normal” has always been the teenage mantra. And while most adolescent girls (and their parents) behold the body changes that accompany puberty with trepidation, “Is this normal?” is a question that weighs heavily on many a young girl’s mind. Here’s a short primer to help alleviate some of the concerns over this stage of development.
WHY DOES PUBERTY OCCUR?
Brain centers, as well as the adrenal glands and ovaries, mature, learn to communicate with one another and produce rising levels of hormones. The adrenal glands secrete male hormones which cause body changes that include growth of hair in the pubic area and under the arms, as well as perspiration, body odor, acne, and, oh yes, an interest in boys. Growth hormone levels increase, causing a spurt in the growth of bones and organs. As a result, a girl’s height increases three and one-half inches a year and her body fat nearly doubles; there is an average weight gain of 15 to 20 over a two to three year period. This growth spurt usually coincides with the beginning of breast development and continues until the onset of menstruation.
As the ovaries mature and respond to increasing amounts of controlling hormones from the pituitary gland in the brain, their follicles (which contain undeveloped eggs) produce estrogen. Eventually the follicles develop sufficiently to release an egg, at which time progesterone is secreted. This is ovulation. As a result of estrogen production, the uterine lining (endometrium) is built up, and when the hormone level falls, the lining sloughs, causing the onset of periods. The very first period, or menses, is called menarche.
WHAT ARE THE STAGES OF PUBERTY?
These stages have been defined according to the organ or system that is developing. The stages were described and named after Tanner, and hence this is called Tanner Staging:
In the case of breast development:
Stage I - no breast tissue
Stage II - breast buds appear, together with a widening of the pigmented area around the nipple (aereola)
Stage III - further growth
Stage IV - the aereola and nipples project above the breast tissue
Stage V - breasts reach a mature contour and projection
While this is going on, pubic hair also goes from stage I to stage V. It first appears as fine, sparse hair, and over the next four years becomes coarse and reaches the inner surface of the thighs.
Finally, menarche occurs, usually within two years of reaching Tanner Stage IV (i.e., almost complete breast development and dense pubic hair growth).
AT WHAT AGE DO EACH OF THESE CHANGES OCCUR?
Breast development can begin as early as eight but as late as 14 (average 10.2 years).
Pubic hair develops between nine and 12 years of age.
Growth spurt, usually begins at age 10 and continues until 13.
Menarche, average age is 12.7; by age 14, 95 percent of girls will have had a period.
Pubertal developmental and first periods occur at a slightly younger age in African-American girls. There is also a correlation between body fat and onset of periods. A critical amount of fat (17 percent of total weight) is needed to start menstruation, and 22 percent to maintain cycles. By 16, most girls have accumulated 27 percent body fat. When young girls become obese, their periods may occur at an earlier than expected age.
WHEN DOES PUBERTY BECOME A MEDICAL PROBLEM?
Since girls differ by genetically and diet-determined body type, the most recognizable milestone in their development is menarche. The time of onset and the nature of subsequent periods, together with menstrual cramps, are the most common issues that cause young teens to see a doctor.
Too Early: If a girl gets her period before the age of nine or 10, she should be seen by her physician. Menarche this early will shorten the duration of her growth spurt and may stunt her ultimate height. Her doctor will assess her height and weight, as well as the height of her parents, and may prescribe medications to shut down production of the pituitary hormones that stimulate the ovaries.
Too Late: If there is no period by age 14, or within two years of breast development, a medical work-up is in order (thin girls who engage in highly competitive sports are an exception; in their case it’s acceptable to wait until they become 16). The work-up will include blood tests for under-active thyroid, undeveloped ovaries, pituitary abnormalities, or genetic disorders. Ultrasound may be needed to make sure the uterus has developed and appears normal. Often birth control pills will be prescribed to bring on cycles and make sure there is sufficient estrogen “on board” so that bones develop and mineralize adequately (lack of estrogen in these crucial years of bone development can lead to osteoporosis).
WHAT’S “NORMAL” DURING THE FIRST FEW YEARS OF MENSTRUAL CYCLES?
During the first two years after menarche, a young teen’s cycles may be irregular. The complicated signals between the brain and ovaries are still not well recognized or organized and even when those cycles occur, they often do so without a true ovulation. (They are anovulatory). Ninety percent of girls will end up having cycles that are within the range of 21 to 42 days, and last from three to 8 days. Although young teens don’t always know how to judge what constitutes a heavy period, in general they should not be changing a pad or tampon more than every three hours. As ovulation and periods become more regular, there an increase in cramps, breast tenderness, and PMS is common. The earlier the menarche, the faster regular ovulatory cycles are established. Girls who reach menarche late experience more anovulatory cycles, and as many as one-third of adolescents will continue to have anovulatory cycles up to and including the fifth year after menarche.
WHEN SHOULD A TEENAGE GIRL SEE A DOCTOR ABOUT HER PERIODS?
If they are very heavy (causing a need to change a pad or tampon every one to two hours), she should be seen to control the bleeding and to rule out a clotting disorder. Von Willebrands disease is an inherited blood disorder causing decreased clotting and is present in one percent of the population. Often the first symptom that indicates this blood problem is heavy menstrual bleeding. Birth control pills usually help stop heavy bleeding and are the first suggested mode of therapy.
If these occur together with acne, obesity and increased hair growth, a condition called polycystic ovarian syndrome (PCOS) may be present. This is a common glandular disorder, which occurs in seven to 10 percent of women. High levels of male hormone and insulin found in many women with PCOS may prevent ovulation. Treatment usually consists of birth control pills and in some cases the oral antidiabetic medication Glucophage (which lowers insulin levels).
Menstrual Cramps (Dysmenorrhea):
This can initially be treated with over-the-counter non-steroidal anti-inflammatory drugs (NSAID’s), such as ibuprofen and naproxen, as well as prescription NSAID’s. Birth control pills will also often help decrease cramps. If pain is still severe despite this therapy, a pelvic exam should be done to rule out infections (remember the average age for first intercourse for girls in the U.S. is 17, and many girls will be active at a younger age) or endometriosis.
Seventy-five percent of young teens perceive that they have a problem with their puberty and/or menstrual cycles. Helping them understand what is happening and making sure they see a doctor, if indeed there is a problem, can make this time of sexual maturation a positive, health-affirming rite of passage.
Dr. Judith Reichman has practiced obstetrics and gynecology for more than 20 years. She is a regular “Today” show contributor.