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menstrual disorders
Abnormalities in the normal menstrual cycle can be a sign of reduced fertility. Menstruation - the monthly bleed - normally follows ovulation (egg release). If there are problems with the process of follicle maturation preventing ovulation, then as a general rule, menstruation does not occur.
This means that the absence of menstruation (in women who are not pregnant) is an important indication that there may be a problem with ovulation. It is therefore advisable for women with an irregular or non-existent menstrual cycle to undergo initial investigations to identify the underlying cause.
Problems relating to ovulation are often caused by hormonal imbalances. In many cases, a woman produces too little of one hormone or too much of another - this is the underlying cause of the disorders outlined below. Luckily, hormonal disruption is not difficult to identify and the treatment (ovulation induction) is simple and relatively effective.
hormonal imbalances
A disturbance in the balance between the different hormones involved in reproduction can lead to reduced fertility in women. Hormonal imbalances can sometimes be traced back to disruptions in the primary glands (hypothalamus, pituitary or ovaries) that produce sex hormones.
- The hypothalamus, pituitary and ovaries send signals back and forth throughout the reproductive process triggering changes in hormone production. A shortage of stimulating hormones is one explanation for a disrupted cycle. The hypothalamus can, for example, be influenced by stress, sickness or some medicines.
- Alternatively the pituitary gland may produce too much of the hormone prolactin (prolactinaemia). If the concentration of prolactin in the blood is too high, it disturbs ovulation (egg release). Prolactinaemia can be caused by benign lumps in the pituitary gland, so if it is diagnosed, tests will be undertaken to investigate this.
- A mal-functioning thyroid gland can also disrupt the hormonal balance and, as a result, ovulation. An increased production of the so-called “male hormones” (androgens) is another cause of disturbed ovulation in women.
By ascertaining an individual woman’s hormone levels, doctors can identify at what level the cause of the ovulation problem lies. The underlying cause is the critical factor in determining the type of treatment that is appropriate. The World Health Organisation (WHO) classifies women with ovulation problems into three different categories. These classifications are based on the level at which the problem lies:
Group 1: | cause situated centrally (brain); occurs in approximately 5-10% |
Group 2: | disturbance of the balance between the pituitary gland and the ovary; 60-85% |
Group 3: | cause lies in the ovaries themselves; 10-30% (An increased prolactin concentration in the blood can be categorised in groups 1 or 2.) |
polycystic ovaries - (PCO)
Polycystic ovaries or PCO, also called Stein-Leventhal syndrome, is a disorder whereby the hormonal balance is disturbed, which in turn disrupts ovulation (egg release). Essentially, the adrenal gland and the ovaries produce excessive amounts of the so-called male hormones (androgens), which leads to an abnormally high production of luteinizing hormone (LH) and an abnormally low production of follicle-stimulating hormone (FSH). As a result, the ovary fills itself with cysts of immature follicles that cannot produce eggs. (Androgens, although viewed as male hormones are actually produced in women as well. Similarly men also normally produce estrogens - the so-called female hormones. In each sex, it is the balance of these hormones that determine their affects.)
Women who suffer PCO can display a range of symptoms including:
- Irregular menstruation
- Enlarged ovaries
- Excessive facial and bodily hair
- Oily skin
- Acne
- Overweight
A diagnosis of PCO can be made on the basis of the clinical symptoms mentioned above, determination of hormone levels and an ultrasound scan of the ovaries. If a woman with PCO displays the described physical symptoms, then the condition is termed Polycystic Ovarian Syndrome (PCOS).
premature menopause
The cause of disrupted cycles can also lie in the ovaries themselves. The menopause marks the end of reproductive life in women and occurs when the ovaries ‘run out’ of eggs. In the event that the ovaries’ egg reserves run out prematurely, a woman can become menopausal before her time.
Normally, the average age for the menopause is 51. If the reserve of eggs runs out earlier, then ovulation does not occur and menopause - the cessation of menstruation - is experienced earlier.
If this happens to a woman under the age of 40, it is termed premature menopause. A premature menopause, also known as premature ovarian failure (POF), occurs in about 1 to 4% of women.
If your sister or mother has experienced premature menopause, then it is important to report this to your doctor, as this condition often runs in families.
