Common Causes of Amenorrhoea


Physiological Causes

  • Pregnancy must always be excluded
  • Lactation
  • Menopause



Iatrogenic Causes

  • Progestogenic contraceptives
  • Therapeautic progesterones


Investigations for Amenorrhoea


Pregnancy Test: essential!

Prolactin: mandatory.

FSH/LH: Increases in primary ovarian failure and decreases in hypothalamic causes.

Pelvic ultrasound: Can define anatomical structures, congenital abnormalities, and PCOS morphology.

Karyotype, if uterus is absent or suspicion of Turners syndrome.

Specific tests for endocrinopathies, where there is clincial suspicion.

    Management of Amenorrhoea


    Must be guided by the diagnosis and fertility wishes. Options include:


    • Treat any underlying causes
    • Attain normal BMI
    • Cabergoline or surgery for hyperprolactinaemia
    • Cyclical withdrawal bleeds (COCP for PCOS)
    • HRT for premature ovarian failure.
    • Relief of genital tract obstruction (cervical dilation, hysteroscopic resection, incision of hymen)
    • Specific treatment for endocrinopathies and tumours.

      Causes of Abnormal Vaginal Bleeding - Organic Causes


      Reproductive Tract Disease

      Pregnancy-related conditions are the most common caues of abnormal vaginal bleeding in women of reproductive age. Implanataion bleeding is also quite common at around the time of the first missed menstrual period.


      Uterine lesions commonly produce menorrhagia or metrorrhagia through increasing the endometrial surface area or causing an inflamed surface.


      Cervical lesions usually result in metrorrhagia (especially post coital bleeding) due to erosion or direct trauma.


      Iatrogenic causes include -     Intrauterine device (IUD).  Oral contraceptives: Are associated with irregular bleeding during the first three months of use. Long-acting progesterone only contraceptives (Implanon) frequently cause irregular bleeding.


      Systemic Disease

       Blood Dyscrasias such as Prothrombin deficinecy may present with profuse vaginal bleeding during adolescence. Other disorders that produce platelet deficiency (leukaemia, severe sepsis) can also present as irregular bleeding.


      Cirrhosis is associated with excessive bleeding, secondary to the reduced capacity of the liver to metabolise oestrogens.


      Hypothyroidism is frequently associated with menorrhagia and/or metrorrhagia. 

      Causes of Abnormal Vaginal Bleeding - Dysfuctional (Endocrinological) Causes


      Anovulatory DUB

      The predominant type in the post-menarcheal and pre-menopausal years, due to alterations in neuroendocrinological function

      Characterised by continuous production of estradiol-17B without corpus lutem formation and progesterone release

      Unopposed oestrogen leads to continuous profileration of the endometrium which eventually outgrows its blood supply and is sloughed in an irregular, unpredictable pattern.



        Ovulatory DUB

        Mid-cycle spotting follwoing the LH surge is usually physiologic.

        Polymenorrhoea is most often due to shortening of the follicular phase of menstruation. 


          Incidence: up to 10% of ovulatory women

          Causes of Abnormal Vaginal Bleeding - Other Causes

          Women with Polycystic Ovary Syndrome (PCOS) are also likely to suffer from oligomenorrhea. PCOS is a condition in which the ovaries become filled with small cysts. Suffering women show menstrual irregularities that range from oligomenorrhea and amenorrhea from one end to very heavy, irregular periods on the other. The condition affects about 6% of premenopausal women and is related to excess androgen production.


          Eating Disorders such as Anorexia Nervosa and Bulimea Nervosa are contributors to Irregular Bleeding. Although poorly understood, it is thought that that the abnormalities are due to the biological support for the disease rather than as a result to nutritional deficiences.


          Diagnosis and Examinations

          Patient age is the most important factor in the evaluation for a potetnial diagnosis.

          For women of reproductive age, ruling out any pregnancy-related complications should be the first priority.

          A complete list of medications is essential to rule out any interferences with normal menstruation.


          Measurment of serum haemoglobin concentration, iron levels and ferritin levels are objective measures of the quantity and duration of menstrual blood loss. Additional laboratoy tests (TSH, coagulation profile) may be indicated.

          A menstrual calander may be helpful in accurately determining the amount, frequency and duration of the bleeding.

          Ovulation can be assessed by careful history-taking and, if available, ovulation prediction kits.

          Further evaluation of the uterus can be achieved in non-pregnant women by performing an endometrial biopsy or hysteroscopy.

          Ultimately, a pelvic ultrasound may also be required if the cause of bleeding cannot be confirmed.




          The majority of women with abnormal vaginal bleeding can be treated medically, particularly in the absence of a structural lesion.

          Oral contraceptives effectively correct the vast majority of common menstrual irregualrities (anovulatory and ovulatory DUB). However, DUB can occasionally present as an acute haemorrhage requiring short term, hgih dose oral or intravenous oestrogen therapy to transiently support the endometrium.

          Non-steroidal-anti-inflammatory drugs (NSAIDs) such as mefenamic acid have been shown to reduce menstrual loss, particularly in ovulatory patients.



          Structural abnormalities frequently require surgical intervention to alleviate symptoms.

          Dilation and Curettage (D&C) can be both diagnostic and therapeautic - especially in women with acute vaginal bleeding, due to endometrial overgrowth.

          Hysteroscopy is a Day surgery proceduare that can be used to diagnose and treat abnormal uterine lesions. The uterine cavity is distended with fluid, allowing direct visualisation of the abnormality and use of hysteroscopic instruments. Endometrial ablation can dramatically reduce the amount of cyclic blood loss.

          Hysterectomy is usually reserved for women with structural lesions not amenable to more conservative surgery (multiple large leiomyomas, uterine prolapse). It may also be indicated in women with persistent DUB, but only if medical therapy has failed.



          Flowchart of Treatment steps - Increasing severity

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