Description

Amenorrhea is the absence of menstruation. It is divided into two categories:

• Primary amenorrhea
  • The failure to begin menstruation by 15 years of age in girls with otherwise appropriate pubertal development or by age 13 years in the absence of secondary sexual characteristics
  • This diagnosis should also be considered if a girl has not menstruated within 3 years of thelarche (after breast development begins) regardless of her age.
• Secondary amenorrhea
  • The cessation of menstruation for 3 cycles or 6 months in girls and women with previously established regular cycles
  • Should not be used when referring to girls who are within 2 years of menarche because regular ovulatory cycles have not yet been established; their periods are unpredictable.

Epidemiology

There is insufficient information about the incidence of amenorrhea in contemporary pediatric populations.

Risk Factors

Common preventable risk factors for amenorrhea include:

• Pregnancy
• Extremes in weight (including that related to obesity, eating disorders and energy imbalance from athleticism)
• Psychosocial stress

General Prevention

• Healthy lifestyle, maintaining a healthy weight
• Avoidance of excessive athletic activity or training
• Management of emotional stress
• Adherence with chronic disease management

Pathophysiology

• Amenorrhea related to estrogen deficiency is associated with poor bone health. These patients may fail to reach peak bone mass and have increased risk of fractures.
• Depending on the underlying etiology, future fertility may be impacted.
• Patients with polycystic ovary syndrome (PCOS) may experience long periods of unopposed estrogens and therefore have an elevated risk of endometrial hyperplasia and an increased risk for endometrial cancer.

Etiology

Menstruation requires the presence of functional female internal genitalia with an intact and patent outflow tract and appropriate stimulation and regulation of the endometrial lining by the hypothalamic–pituitary–ovarian axis. Disruption at any level of the hormonal axis can lead to amenorrhea.

Commonly Associated Conditions

• The most common chromosomal abnormality associated with primary amenorrhea is Turner syndrome.
• Amenorrhea associated with obesity or PCOS is becoming a common cause of both primary and secondary amenorrhea among adolescents in developing countries.