Amenorrhea

Normal menstruation

  1. Average age of onset is 12.8 years. Slightly lower in African Americans. 
  2. Usually 2-2.5 years after the development of breast buds and 1 year after growth spurt
  3. The initial cycles are anovulatory and regularity may not be established for 1-2 years. Each individual's cycles are usually regular and the average amount of blood lost per cycle is 30-40 cc.

Primary amenorrhea

  1. Absence of menses by age 16 when there is normal pubertal growth and development 
  2. Absence of menses by 14 years of age with absence of normal pubertal growth and development.
  3. No menses 2 years after sexual maturation is complete.

Evaluation of primary amenorrhea

  1. History
    1. Growth
    2. Development
    3. Nutrition, diet, weight loss
    4. Mother's and sister's age at menarche
    5. Are there any chronic diseases?
    6. Medications
    7. Exercise history
  2. Physical Examination
    1. Sexual development
    2. Height and weight (chart the results)
    3. Skin and hair distribution
    4. Cranial nerve and funduscopic examination with visual fields
    5. Thyroid should be palpated
    6. Pelvic examination looking for the presence of a vagina, hymen, uterus, and ovaries.
  3. Etiologies associated with findings
    1. No breast development and uterus present
      1. Most common is gonadal dysgenesis. XO( Turner's syndrome; ‘webbed’ neck, short stature, increased distance between nipples, impaired hearing, coarctation of the aorta, ovarian dysgenesis) or other X chromosome abnormality. with elevated FSH and LH.
    2. Normal breast development and absent uterus
      1. Testicular feminization (XY) that have testosterone insensitivity. They are phenotypically females. There is decreased pubic and axillary hair. 
      2. Mullerian agenesis(XX) with normal hormones
    3. No breast development and absent uterus
      1. Very rare. XY that have normal Mullerian duct inhibiting factor but do not produce enough testosterone for normal male external genitalia.
    4. Normal breast development and uterus present
      1. Usually structural defect. Intact hymen or vaginal septum. XX genotype.

Secondary Amenorrhea

  1. Absence of 3 cycles or 6 months without period after gynecological age (time since menarche) of 24 months (this time point was chosen because regular menstrual cycles are not established until 2 years after menarche).
  2. Most commonly results from disruption of the hypothalamic-pituitar-ovarian axis.
  3. Common Etiologies
    1. Must rule out pregnancy first (pregnancy is the second most common cause of secondary amenorrhea; primary cause is physical or emotional stress-related condition).
    2. Anorexia nervosa/disordered eating (secondary amenorrhea can be first sign of anorexia)
      • Watch for athletes’ triad:
        1. Amenorrhea
        2. Disordered eating pattern
        3. Osteoporosis
    3. Exercise (physical stress)
    4. Emotional stress
    5. Inflammatory bowel disease
    6. Diabetes mellitus
    7. Hyperthyroidism
    8. Pituitary adenoma or Craniopharyngioma
    9. Illicit drugs
    10. Polycystic Ovary Syndrome
      • A.k.a. functional ovarian hyperandrogenism: elevated ovarian androgen and elevated LH/FSH ratio à chronic anovulation.
      • Associated with hirsutism and hyperinsulinism; look for acanthosis nigricans
  4. History
    1. diet including amount of calories. Weight loss recently?
    2. Exercise habits
    3. Medications including street drugs
    4. Headaches and visual changes. 
    5. Symptoms of increased thyroid activity such as weight loss, sweating, weakness, diarrhea
    6. Galactorrhea
  5. Physical examination
    1. Height, weight, BP, pulse, temperature
    2. fundoscopic examination and visual fields
    3. Findings of pregnancy including tender breast and enlarged uterus
    4. External genitalia changes of virilization including male hair pattern and clitoromegaly
    5. hirsuitism
    6. galactorrhea- associated with prolactin excess and pituitary adenoma
  6. Treatment
    1. Menses can resume if the underlying factor can be removed, especially in the case of physical/emotional stress and/or anorexia.
    2. Polycystic Ovary Syndrome can be managed with oral contraceptives (decrease GnRH release from hypothalamus via negative feedback, leading to a reduction in ovarian androgen production).

Evaluation of Amenorrhea- determined by history and physical examination

  1. CBC and differential
  2. FSH and LH
  3. CT of the head
  4. Ultrasound of the abdomen and pelvis
  5. T4 and TSH
  6. Chromosomes

Reference

  1. Bloomfield D. Secondary Amenorrhea. Pediatrics in Review. 2006. 27:113-114
  2. Polaneczky, Margaret and Slap, Gail B. Menstrual Disorders in the Adolescent: Amenorrhea. Pediatrics in Review February 1992
  3. Prose, Ford, and Lovely  Evaluating Amenorrhea.  The pediatricians role.  Contemporary Pediatrics Oct. 1998