Secondary amenorrhea: the causes of the lack of menstruation

Missing a period for at least 4 months is called secondary amenorrhea. And when it occurs, some clinical investigations are necessary.

Usually secondary amenorrhea does not appear suddenly but follows a condition of oligomenorrhea (cycles longer than 36 days).

Excluding pregnancy which evidently suspends the cycle for nine months and beyond, a prolonged absence must take into consideration other causes which are divided into organic and dysfunctional.

The ones that occur most frequently are:

• Amenorrhea due to polycystic ovary syndrome (36.9%)
• Premature menopause amenorrhea (23.6%)
• Amenorrhea due to hyperprolactinaemia (16.9%)
• Weight-related amenorrhea (9.8%)
• Amenorrhea due to hypogonadotropic hypogonadism (5.9%)
• Amenorrhea due to hypopituitarism (4.4%)
• Excessive physical activity amenorrhea (2.5%)

Organic causes of secondary amenorrhea

1. Among the most common causes we find hyperandrogenism . It is a condition in which too high levels of androgens are found which can cause amenorrhea. The most common form of hyperandrogenism is PCOS.
2. Infectious causes : Meningitis or encephalitis can damage the hypothalamus and/or pituitary and cause secondary amenorrhea
3. Neoplasms involving the central nervous system, pituitary and hypothalamus. The most frequent are pituitary adenomas which are divided into secretory and non-secretory and micro and macro-adenomas. The most common are prolactin-secreting adenomas .
4. Genital malformations : the most common conditions are adhesions or synechiae which more or less completely occlude the uterine cavity and/or the cervical canal. They can be and are due to Ashermann’s syndrome. Synechiae are a consequence of revisions of the uterine cavity or lacerations from childbirth or cesarean section, or adhesions due to previous genital infections.
5. traumatic causes : which may have injured the structures of the reproductive axis (hypothalamus-pituitary-ovary)
6. Vascular causes : This is post-infarction piphyseal necrosis, often caused by postpartum hemorrhagic shock (Sheenan syndrome). It is manifested by amenorrhea due to hypogonadotropic hypogonadism, lactotropic, corticotropic and thyrotropic function deficits.
7.  Dysmetabolic causes: In patients who have undergone a gastrectomy or who have malabsorption due to gastro-intestinal pathologies, amenorrhea may occur due to a lack of quality and quantity of nutrients necessary for hormonal synthesis.

Dysfunctional causes of secondary amenorrhea

It is a common form of amenorrhea that mainly affects teenage girls.

The causes in this case are linked to conditions of physical, metabolic or emotional stress. It is a situation that occurs, for example, in girls who suffer from eating disorders such as anorexia. Weight loss that is too rapid or that leads to a very low body mass index can cause secondary amenorrhea. Or it can occur in those who do a lot of physical activity (marathon runners, dancers, gymnasts, etc.) and again in those who have suffered a strong mourning or are experiencing a separation or in any case an important psycho-emotional stress .

In all these cases, a detailed medical history is important in order to choose the appropriate therapy.