Dysfunctional uterine bleeding: What is it?
Dysfunctional uterine bleeding or DUB is the most common cause of abnormal uterine bleeding in women. This is mainly because of hormonal disturbances in the body usually causing a failure of the egg to be released from the ovary. It commonly occurs in older women who are above 45 or in young adolescent girls. It can also occur when ovulation is normal but other hormonal factors are causing the abnormal bleeding. Most of the time DUB is not a serious condition and can be controlled by giving hormones, and NSAIDs such as Ibuprofen.
Who is at a risk of Abnormal Uterine Bleeding?
In young girls, the most common cause of hormone disturbance is the failure to ovulate because the girl is still growing up and the systems are still immature. The ovary is not able to release an egg. The release of an egg is an important part part of the menstrual cycle. If a girl's body doesn't release an egg, it is called anovulation.
Anovulation or the failure to ovulate usually happens early on when the girl first starts menstruating. For many months or even years the cycles can be anovulatory meaning that no egg is being released. This can lead to less frequent or heavy periods. The cycles can be longer (more than 21 days) or shorter. The periods will not be accompanied by any pain.
(Anovulatory uterine bleeding in girls can also be due to polycystic ovarian syndrome, thyroid problems, over exercising, stress, eating and bleeding disorders. These must be ruled out to diagnose DUB.)
Does it have a pattern?
The bleeding in such girls occurs at unpredictable times and in unpredictable patterns. This is called metrorrhagia. It is not accompanied by cyclic changes in basal body temperature as progesterone is not being produced by the ovary.
In women with chronic anovulation, meaning where ovulation has not resolved normally, infertility may also be present.
Are older women affected too?
In older women who are going through the menopause, DUB may be an early sign that the ovaries are becoming insufficient or failing to produce enough oestrogen to trigger ovulation. This means that the waning out process of the reproductive system has begun.
(About 20% of women with endometriosis also have anovulatory DUB. The reason for the ovary failing to release the egg in these cases is not clear.)
Most cases of DUB are because of this anovulation factor. Only about 10% of cases of DUB are ovulatory that means that ovulation is not affected and that the bleeding is because of other hormonal mechanisms.
What are the indicators?
Measuring the serum progesterone levels during the luteal phase (after day 14 of a normal menstrual cycle) can indicate whether ovulation is taking place or not. A level of ≥ 3 ng/mL (≥ 9.75 nmol/L) means that ovulation has occurred.
Ovulatory DUB may occur in polycystic ovarian syndrome (because progesterone secretion is prolonged) and in cases of endometriosis where ovulation remains unaffected.
Women with ovulatory DUB have regular menstrual cycles but the periods are heavy. That is they have menorrhagia, very heavy bleeding during a regular period or prolonged bleeding (more than 8 days). They have other normal pre-menstrual symptoms such as breast tenderness, mid-cycle cramping pain (mittelschmerz) and a rise in basal body temperature after ovulation and sometimes pain during menstruation.
When the amount or timing of vaginal bleeding is not like normal menses DUB must be evaluated for. DUB is a diagnosis of exclusion. Other conditions that can cause similar bleeding must be excluded. Pregnancy should be excluded. Coagulation disorders should be excluded. Structural abnormalities and other causes of abnormal bleeding must be excluded first before a diagnosis of dysfunctional bleeding is made.