I generally consider 16 years the upper cutoff age for menarche. If you are 14 and have not yet had your first period, don’t worry. Most often the cause is simply late puberty. Some girls mature faster than others, and as long as you have some signs of puberty — pubic hair and breasts that are beginning to develop — chances are that you are a late bloomer.

A second cause can be heavy athletic training. Occasionally the mother of a young teenager tells me during her own appointment that she is worried because her daughter has not started to menstruate. When I ask what sports the daughter plays, sometimes the mother will say, “Oh, my daughter is extremely athletic. She runs, she plays tennis, she swims.” I point out that running, swimming, and playing tennis are wonderful activities for adolescent girls, but all that exercise keeps body weight down, leads to a high proportion of muscle to body fat, and often delays menarche. I usually suggest that girl and mother talk to their pediatrician (most girls this age still go to a pediatrician for their general care). If their pediatrician is not well versed in these matters, he or she can always consult with a gynecologist or an endocrinologist.

There are a couple of anatomical causes for primary amenorrhea, but they are quite rare. One is an imperforate hymen, which means that the hymen is completely closed, leaving no way for the menstrual flow to exit the body.

Tracey was sent to me by her pediatrician when she was 14 years old, because she had cramps every month but no menstrual flow. When I checked her, I discovered that she had an imperforate hymen. The answer was a simple surgical procedure, performed under anesthesia, during which we cut an X-shaped opening in her hymen. When we did so, we found blood from her previous menstrual periods collecting in her vagina.

The surgery solved her problem, and I didn’t see Tracey for about ten years. After college and marriage, she came back for prenatal care and the delivery of her first child, a birth that took place with no problems at all.

A few rare genetic conditions can cause amenorrhea. One of these is androgen insensitivity syndrome; the other is Turner syndrome.

Androgen Insensitivity Syndrome

This rare condition, also called testicular feminization syndrome, develops in women who have XY chromosomes (like males) rather than XX chromosomes (like females). A woman with this condition is born without a uterus or fallopian tubes. Instead of ovaries, she has incompletely developed testes, which nevertheless can produce testosterone. The testes may be in either her abdomen or her groin area. After puberty these women may have no pubic hair or only a small amount, and their breasts usually do not have much glandular tissue. Women with androgen insensitivity syndrome never menstruate and cannot bear children, but their psychological outlook and behavior are feminine, so they often adopt children. Their bodies are apt to be slender and strong.

The condition is caused by a recessive gene that interferes with proper sexual differentiation. During early fetal life all embryos have the potential to become either males or females, but at the seventh week or so, a gene on the Y chromosome (the one that males have) causes the testes to develop. If the embryo has no Y chromosome, then ovaries develop at about the eleventh week of fetal life.

Once the testes have formed, the fetus responds to male hormones and the other male internal and external structures form. An embryo with an XY genetic makeup that carries the faulty recessive gene will have testes, but the fetal cells do not respond to the masculinizing hormones (androgens) that would continue the process, so the male organs do not develop fully. The condition is diagnosed by a physical exam, blood testing for testosterone levels, and chromosomal testing.

Turner Syndrome

Turner syndrome (also called gonadal dysgenesis) is another rare genetic condition, caused by complete or partial absence of one of the two X chromosomes that women normally have. The cause is not yet known, but Turner syndrome has not been associated with any of the environmental factors that sometimes cause genetic problems. Usually the condition turns up at adolescence, when the girls affected fail to develop adult sex characteristics and do not start menstruating. These girls have a distinctive physical appearance: they are short (the average adult height is 4′ 8″); they may have a webbed neck, many moles, no breast development, and childlike genitals. Blood tests can show whether hormonal levels are normal. Turner syndrome can be detected during fetal life through genetic testing. Estrogen replacement therapy can encourage normal breast development and menstruation. Sometimes growth hormone is given to increase height. Most women with Turner syndrome do not ovulate, but modern reproductive techniques such as fertilization with donor eggs can sometimes help these women to become pregnant.

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