A1. Amenorrhea; classifications, diagnosis and therapy

Last updated on June 25, 2021 at 11:00

Note to self and others: the seminar uploaded to Teams called “RP – Congenital anomalies of the gen.tract – Gomány” includes a section on differential diagnosis of primary amenorrhoea which I didn’t know about when writing this topic.

Primary amenorrhoea


Amenorrhoea means that there is a loss of menstruation. We can distinguish primary and secondary amenorrhea.

Primary amenorrhea is the failure of menstruation to occur by age 16, despite normal growth and secondary sexual characteristics, or by the age of 14 if there are no secondary sexual characteristics.


  • Gonadal dysgenesis – (most common cause)
    • = absence of germ cells in the gonads
    • Turner syndrome (45XO)
    • Swyer syndrome
  • Constitutional delay
    • = normal pubertal development, but adrenarche and gonadarche occur at a later age
  • Müllerian agenesis
    • = failed fusion of Müllerian ducts, causing atretic uterus, cervix, and upper third of vagina
    • Also called Mayer-Rokitansky-Küster-Hauser syndrome or MRKH syndrome
  • Androgen insensitivity
    • = androgen receptor mutation
  • Prolactinoma
  • Hypogonadotropic/hypothalamic hypogonadism
    • = hypogonadism due to decreased GnRH
    • Kallmann syndrome (anosmia + primary amenorrhoea)

All causes of secondary amenorrhoea can also cause primary amenorrhoea.

Diagnosis and evaluation

It’s important to measure the following:

  • History taking
  • Physical examination, especially of the breasts
    • The presence of breasts is a marker of oestrogen action and therefore function of the ovary
  • Pelvic ultrasound – to look for uterine, cervical, and/or vaginal abnormalities or absences
  • FSH
  • hCG – to rule out pregnancy
  • Karyotyping

If breasts are present, the following disorders are most likely:

  • Müllerian agenesis
  • Androgen insensitivity
  • Vaginal septum or imperforate hymen
  • Constitutional delay

In Müllerian agenesis and androgen insensitivity the absence of the uterus is visible on ultrasound. Vaginal septum and imperforate hymen can be diagnosed with transvaginal, translabial and/or transabdominal ultrasound.

If breasts are absent and the FSH is high, gonadal dysgenesis like Turner syndrome is most likely. Karyotyping should be performed to diagnose them.

If breasts are absent and the FSH is low, the following disorders are most likely:

  • Constitutional delay
  • Prolactinoma
  • Kallmann syndrome
  • Functional hypothalamic amenorrhoea
  • PCOS

Prolactin level can rule out prolactinoma. Anosmia indicates Kallmann syndrome.


Treatment involves management of the underlying cause. Anatomical abnormalities must be treated by surgery. For more information on treating intersexual conditions, see topic B5.

Secondary amenorrhoea


Secondary amenorrhoea is the loss of menstruation for 3 – 6 months or more in a person who have had normal menstrual cycles.


  • Pregnancy – most common cause
  • Ovarian amenorrhoea
    • Polycystic ovary syndrome
  • Hypo/hyperthyroidism
  • Hyperprolactinaemia
    • Antipsychotics
    • Prolactinoma
  • Pituitary amenorrhoea (due to hypopituitarism)
    • Sheehan syndrome
    • Panhypopituitarism (Simmonds syndrome)
    • Brain irradiation
  • Functional hypothalamic amenorrhea
    • Excessive exercise
    • Anorexia nervosa
    • Stress
  • Asherman syndrome (iatrogenic intrauterine adhesions)

Diagnosis and evaluation

It’s important to measure the following:

  • History taking
  • Physical examination
  • hCG – to rule out pregnancy
  • FSH
  • TSH
  • Prolactin

Pregnancy is the most common cause, so hCG must be measured.

Elevated FSH indicates ovarian insufficiency, e.g. caused by PCOS. Elevated TSH indicated hypothyroidism.

If the prolactin is elevated and there is galactorrhoea, a pituitary MRi should be performed, unless the patient is on antipsychotics.


Treatment involves management of the underlying cause.

Hyperprolactinaemia is treated with dopamine agonists like bromocriptine or cabergoline.

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2 thoughts on “A1. Amenorrhea; classifications, diagnosis and therapy”

  1. I don’t think it is advisable to try and diagnose an imperforate hymen with a transvaginal US probe. 😀

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