Absence of menstrual periods

Sometimes there is the absence of a menstrual period in a woman of reproductive age. Physiological states of absence of menstruation are seen, most commonly, during pregnancy and lactation (breastfeeding), the latter also forming the basis of a form of contraception known as the lactational amenorrhoea method. Outside of the reproductive years there is absence of menses during childhood and after menopause.

Amenorrhoea is a symptom with many potential causes. 

• Primary amenorrhoea (menstruation cycles never starting) may be caused by developmental problems such as the congenital absence of the uterus, failure of the ovary to receive or maintain egg cells. Also, delay in pubertal development will lead to primary amenorrhoea. In most cases a diagnosis can be made through an exact evaluation of the internal sexual characteristics. If the secondary sexual characteristics are inadequately pronounced (infantile, virilised), a large number of diseases must be considered (delayed puberty, Turner syndrome, androgen receptor defects) whose clarification should at best be carried out in a special endocrinological consultation.
• Secondary amenorrhoea (menstruation cycles ceasing) is often caused by hormonal disturbances from the hypothalamus and the pituitary gland, from premature menopause or intrauterine scar formation. If the period fails to appear for more than three months although a spontaneous menstruation took place previously, then one speaks of a secondary amenorrhoea. It goes without saying that in this situation a pregnancy must be excluded. In order to prove at which level the disorder has occurred, the provision of the following hormone analysis should be adhered to- FSH (follicle-stimulating hormone), LH (luteinizing hormone), estradiol, testosterone, androstendione, prolactin and TSH (thyroid-stimulating hormone). At the same time, the sonographic image of the ovaries and the endometrium is relevant.

Amenorrhoea is associated with some diseases such as Turner’s syndrome, hyperprolactinemia, anorexia nervosa, Asherman syndrome and Müllerian agenesis. 

Turner’s syndrome

Turner’s syndrome is a syndrome of defective gonadal development in phenotypic females mostly associated with the karyotype 45,X. Patients generally present with primary amenorrhoea with failure to develop secondary sex characteristics (sexual infantilism). Interestingly menarche and ovarian function are essentially regulated by two genes on X chromosome. Most women with Turner syndrome have only one copy of the gene in each cell instead of the usual two copies. 

Hyperprolactinemia

Prolactin (PRL) is one of several hormones that are produced by the pituitary gland. PRL has many different roles throughout the body, and most of those are clearly shown as clinical symptom. Perhaps the most important classical role of prolactin is to stimulate milk production in women after the delivery of a baby. During the first several months of breastfeeding, the higher basal prolactin levels also serve to suppress ovarian cyclicity, through the inhibition of pituitary hormones, mainly via LH suppression. This is the reason why women who are breastfeeding do not get their periods and therefore do not often become pregnant. In actively breastfeeding mothers the related hyperprolactinaemia persisting even over a year. Clinically significant elevation of PRL levels may cause infertility in several different ways. Prolactin may stop a woman from ovulating. If this occurs, a woman’s menstrual cycles will stop.

Anorexia nervosa

The unlimited availability of nutrients, in association with reduced energy expenditure, leads to alterations in many metabolic pathways and to impairments in the finely tuned inter-relation between energy metabolism and reproduction, thereby affecting female fertility. Low leptin (a hormone made by adipose cells that helps to regulate energy balance by inhibiting hunger) serum concentrations were observed in amenorrheic athletes and in women with anorexia nervosa and could, at least in part, explain the hypothalamic amenorrhea affecting those patients.

Asherman syndrome

Asherman syndrome is characterized by variable scarring inside the uterine cavity and it is also cause of menstrual disturbances, infertility and placental abnormalities. Intrauterine adhesions can lead to partial or complete dysfunction of the endometrium with impairment of fertility and menstrual pattern amenorrhea. 

Müllerian agenesis

In women with primary amenorrhea, approximately 15% have abnormal genital examination, with Müllerian agenesis being the second most frequent cause (10%). It is a congenital aplasia (defective development or congenital absence of an organ or tissue) of the uterus and the upper part (2/3) of the vagina. 

Amenorrhoea is also asociated with others conditions (premature ovarian failure, endometrial hyperplasia, cervical stenosis) but there are rare.