What Causes Amenorrhea?

What Causes Amenorrhea?

Amenorrhea is a condition when women do not menstruate for more than three cycles or three months. Any interruption in the normal hormonal cycle of the body due to various reasons can lead to amenorrhea. There are two types of amenorrhea

  • Primary amenorrhea
  • Secondary amenorrhea

The primary amenorrhea is when a girl doesn’t get her first menstruation even after the age of 16. The secondary amenorrhea is when a woman who had normal cycles previously, experience no periods for more than three months.

For proper treatment, it is important to know what can cause amenorrhea. Let discuss.

What Causes Amenorrhea?

There are many reasons for amenorrhea. The natural reasons such as pregnancy, breastfeeding and menopause, are completely normal as every woman may experience this at least once in her lifetime. Also, due to contraceptive pills or IUD, one may have a few episodes of no periods due to cycle suppression. Apart from these reasons, if a woman experiences amenorrhea, then it could be a sign of a medical problem or side-effect of some other medications.

The causes of amenorrhea may vary depending on its type.

Causes of Primary Amenorrhea

  • A genetic disorder such as turner’s syndrome can hinder normal sexual maturation in girls
  • Hyperandrogenism or high levels of male hormones in girls can interrupt the menstruation
  • Anatomical abnormalities such as
    • Mullerian defects wherein the uterus and Fallopian tubes may be missing or not formed correctly.
    • Intrauterine adhesion
    • The Mayer-Rokitansky-KusterHauser (MRKH) syndrome in which there is no vaginal opening

Causes of Secondary Amenorrhea

  • Low body weight or low body mass index (below 19) can interrupt the normal hormonal functioning. This can happen to women with an eating disorder such as anorexia or bulimia.
  • Medications used for cancer, blood pressure, allergy, depression, anxiety, psychosis etc
  • Excessive exercises can affect the menstrual cycles due to loss of body fat and over expenditure of energy
  • Extreme stress can interfere with the brain's hormonal signals to the ovaries
  • Use of drugs can hamper the hormonal cycles and use of alcohol lead to malnutrition
  • Premature menopause happens due to low ovarian reserves in women, as a result, the menstruation stops
  • Asherman’s syndrome or uterine scarring caused due to a C-section, D&C or some other treatment can lead to building up of the scar tissues in the uterine lining
  • Hormonal imbalance in the body due to an overactive thyroid gland, PCOS or a pituitary tumor

Evaluation of Amenorrhea

The basic requirement for normal menstrual function includes four anatomically and functionally distinct structural components - the genital outflow tract(uterus and vagina), ovary, pituitary and hypothalamus - thus providing a natural hierarchy for organizing the diagnostic evaluation of amenorrhea

Disorders of the genital outflow tract and uterus

  • Imperforate hymen
  • Transverse vaginal septum
  • Cervical atresia/stenosis
  • Mullerian agenesis
  • Androgen insensitivity syndrome
  • Ashermans syndrome

Disorders of the Ovary

  • Gonadal dysgenesis
  • Turners Syndrome
  • Swyers Syndrome
  • Premature ovarian failure

Disorders of the pituitary

  • Pituitary tumours
  • Empty sella syndrome
  • Sheehans syndrome

Disorders of Hypothalamic function

  • Hypothalamic amenorrhea
  • Eating disorders
  • Anorexia nervosa
  • Bulimia Nervosa
  • Exercise induced amenorrhea
  • Congenital GnRH deficiency

The evaluation of primary amenorrhea is done at these levels

  • Detailed history along with family history
  • Physical examination
  • Ultrasonography
  • MRI pelvis
  • Hormonal evaluation - FSH, LH, Estradiol
  • Karyotyping
  • Fragile X mutations
  • Autoimmune screening
  • TSH and prolatin levels
  • MRI brain
  • BHCG for pregnancy

It has to be remembered that all investigations will not be done in all who present with amenorrhea. The sequence of investigations will be guided based on the history and physical examination.