Primary amenorrhoea, or failing to commence menstruation, can be caused by a number of congenital and hormonal factors. In rare cases, patients are found not to have a uterus. Doctors describe four categories which are based on the presence or absence of a uterus and on whether breast development occurs.
No breast development, but a uterus can be seen
In this group, four main conditions are identified:
- The hypothalamus does not secrete GnRH because of a functional disorder.
- The pituitary gland does not secrete FSH and LH.
- Congenital abnormalities of the ovaries lead to absent ovulation and menstruation. These include the rare condition known as resistant ovary syndrome in which the ovary cannot respond to FSH, and the chromosomal abnormalities like Turner’s syndrome.
- Lesions or tumours affect the function of the hypothalamus or pituitary glands.
Breast development, but no uterus
Two very rare conditions are associated with breast development and a congenitally absent uterus. In the first, the uterus is absent, but the ovaries function and ovulation occurs. The other is an extremely rare condition known as androgen-insensitivity syndrome where the foetus has an inherited ‘lack of response’ to the androgen dihydrotestosterone. This leads to the development of female genitalia, but no uterus. This is almost always undetected until a reason is sought for primary amenorrhoea.
No breast development, uterus absent
These very rare congenital conditions are caused by genetic abnormalities.
Breast development, uterus present
This category is associated with an abnormality of the hypothalamic-pituitary-ovarian axis; or the causes of secondary amenorrhoea listed in Table 13.1 may also be responsible. Rarely, blockages in the vagina, such as a transverse vaginal septum or an imperforate hymen may need correcting so that the outflow of menstrual blood can occur.
The medical diagnosis of the causes of primary amenorrhoea follows a fairly routine pattern. In many cases, there is no major physical problem, and the onset of puberty has simply been delayed. In these cases, menstruation will commence in due course. Delayed onset of puberty, however, is a diagnosis of exclusion, and most doctors will want to make absolutely sure that this diagnosis is correct.
Breast development indicates either that ovarian oestrogen is being produced or that oestrogens are being produced by conversion of androgens in the fat. Because full breast development will only occur in the presence of ovarian oestrogens, examination of the breasts gives important information about the causes of the primary amenorrhoea.
Attaining a normal height for age is also important because some of the more common chromosomal abnormalities, such as Turner’s syndrome, are associated with a short stature.
The next step is an abdominal ultrasound to determine whether a uterus is present. This allows any uterus, tubes, ovaries and vagina to be seen.
When breast development is normal and the uterus is present and looks normal, the next step is to take blood tests to try to determine if a hormonal abnormality is associated with the problem (). Usually the levels of FSH, LH and prolactin are checked. Normal levels of all three are seen in delayed puberty; a high LH with a low FSH may be present in polycystic ovarian syndrome (the ultrasound findings will usually show the ovarian follicles typical of PCOS); a high prolactin level might have physiological causes or indicate a pituitary tumour called prolactinoma; and a high FSH and LH might suggest that the ovary is not responsive to FSH.
Selections from the book: “ Women, hormones and the menstrual cycle. Herbal and medical solutions from adolescence to menopause”. Edited by Ruth Trickey, 2004.