The median age for menarche is approximately 12.8 years. However, the range varies widely (from 9.1 to 17.7 years of age). The incidence of primary amenorrhea in the United States is less than 0.1%.

Primary amenorrhea is not considered to have occurred until a girl is beyond age 16 without the onset of menses, if she has undergone other normal changes that occur during puberty. Primary amenorrhea may occur with or without other signs of puberty.

There are multiple causes for primary amenorrhea:

• Normal delay of onset (up to age 14 or 15)
• Drastic weight reduction (resulting from poverty, fad dieting, anorexia nervosa, bulimia, very strenuous exercise, or other cause)
• Congenital abnormalities of the genital system (absence of the uterus or vagina, vaginal septum, cervical stenosis, imperforate hymen)
• Hypoglycemia
• Extreme obesity
• Gonadal dysgenesis
• Chromosomal abnormalities such as Turner's syndrome (XO), or Swyer's syndrome (XY)
• Hypogonadotropic hypogonadism
• Testicular feminization syndrome
• True hermaphroditism
• Chronic illness
• Malnutrition
• Cushing's disease
• Cystic fibrosis
• Congenital heart disease (cyanotic)
• Craniopharyngioma, ovarian tumors, adrenal tumors
• Hypothyroidism
• Galactorrhea
• Adrenogenital syndrome
• Prader-Willi syndrome
• Polycystic ovarian disease
• Congenital adrenal hyperplasia
• Pregnancy

• Absence of the first menstrual period by age 16, with or without changes of puberty

• Medical history
• Physical examination
• Urine pregnancy test
• Progesterone withdrawal
• Chromosome analysis
• Serum chemistry (serum gonadotropin)
  • LH
  • FSH
  • Prolactin
  • TSH
  • T3 and T4
• Urine chemistry, 17-ketosteroids
• Head CT
• Head MRI scan
• Ultrasound, pelvic region
• Laparoscopy

Treatment depends on the cause of the amenorrhea.

Pituitary tumors, located in the brain, are usually treated with bromocriptine, a drug that inhibits the abnormally high prolactin secretion caused by these tumors. Surgical removal may also be necessary. Radiation therapy is usually reserved for situations in which other medical or surgical treatment regimens are not successful.

Young women with primary amenorrhea found to be caused by developmental abnormalities (which may result when the parts of the female reproductive system did not form properly before birth) may require hormonal supplementation, surgery, or both.

In any case, psychosocial support and counseling for the patient and family is necessary to address specific concerns and provide guidance regarding anticipated sexual development.

If the problem causing the amenorrhea is not correctable, then the patient and health care provider should consider the possibility of creating pseudomenstruation. This is a menstrual period that is caused by hormonal treatment rather than natural causes.

For women who do not have other reproductive abnormalities, work up for amenorrhea is delayed until after age 16.

If the condition is caused by systemic disease, treatment of the disease should allow menarche to begin.

Overall the prognosis is good, depending on the cause of the amenorrhea. If the amenorrhea is caused by one of the following conditions, there is a good possibility of correcting the amenorrhea, through medication, lifestyle change, or surgery:

• Normal delay of onset (up to age 14 or 15)
• Drastic weight reduction (resulting from poverty or fad dieting)
• Hypoglycemia
• Extreme obesity
• Hypogonadotropic hypogonadism
• Chronic illness
• Malnutrition
• Congenital heart disease (cyanotic)
• Hyperthyroidism
• Imperforate hymen
• Adrenogenital syndrome

If the amenorrhea is caused by one of the following conditions, it is unlikely that the amenorrhea can be corrected by any intervention:

• Congenital abnormalities of the genital system
• Gonadal dysgenesis
• Turner's syndrome (XO)
• Testicular feminization syndrome
• True hermaphroditism
• Cystic fibrosis
• Craniopharyngioma
• Prader-Willi syndrome

Note: If the amenorrhea cannot be corrected, as long as there is a uterus, it may be possible to create a pseudomenstruation with medications to help the young woman feel more like her friends and/or family.

Psychological distress or crisis about being different from friends or family can occur.

Call your health provider if your daughter is older than age 16 and has not yet begun menstruating.