Dysfunctional Uterine Bleeding (DUB) is an abnormal genital tract bleeding based in the uterus and found in the absence of demonstrable structural or organic pathology. It is usually due to hormonal disturbances:
Diagnosis must be made by exclusion, since organic pathology must first be ruled out.
It can be classified as ovulatory or anovulatory, depending on whether ovulation is occurring or not.
10% of cases occur in women who are ovulating, but progesterone secretion is prolonged because estrogen levels are low. This causes irregular shedding of the uterine lining and break-through bleeding. Some evidence has associated ovulatory DUB with more fragile blood vessels in the uterus.
It may represent a possible endocrine dysfunction, resulting in menorrhagia or metrorrhagia. Mid-cycle bleeding may indicate a transient estrogen decline, while late-cycle bleeding may indicate progesterone deficiency.
About 90% of DUB events occur when ovulation is not occurring (Anovulatory DUB). Anovulatory menstrual cycles are common at the extremes of reproductive age, such as early puberty and perimenopause (period around menopause). In such cases, women do not properly develop and release a mature egg. When this happens, the corpus luteum, which is a mound of tissue that produces progesterone, does not form. As a result, estrogen is produced continuously, causing an overgrowth of the uterus lining. The period is delayed in such cases, and when it occurs menstruation can be very heavy and prolonged. Sometimes anovulatory DUB is due to a delay in the full maturation of the reproductive system in teenagers. Usually, however, the mechanisms are unknown.
The etiology can be psychological stress, weight (obesity, anorexia, or a rapid change), exercise, endocrinopathy, neoplasm, drugs, or it may be otherwise idiopathic.
Assessment of anovulatory DUB should always start with a good medical history and physical examination. Laboratory assessment of haemoglobin, luteinizing hormone (LH), follicle stimulating hormone (FSH), prolactin, T4, thyroid stimulating hormone (TSH), pregnancy (by βhCG), and androgen profile should also happen. More extensive testing might include an ultrasound and endometrial sampling.
However, physicians with a solid knowledge of menstrual physiology and a thorough approach to differential diagnosis can evaluate and manage the problem with confidence.
Normal menstrual physiology
A brief review of normal menstrual physiology may be helpful in understanding abnormal uterine bleeding. The typical menstrual cycle has two phases: proliferative and secretory. A 28 day cycle is divided into
the first 14 days where the follicle grows is called the proliferative or follicular phase
the second 14 days after the follicle has ruptured [ovulation] and released the ovum [egg] is called the secretory or luteal phase
The proliferative phase is characterized by a predominance of estrogen over progesterone and a build up of endometrium. The secretory phase begins after ovulation triggers progesterone production. This phase is marked by a reaction to the combination of estrogen and progesterone and stabilization in the thickness of the endometrium.
Menstrual bleeding occurs after secretion of estrogen and progesterone tapers off. Early during menses, thrombin plugs restrain blood loss, but later, vasoconstriction of the spiral arterioles is responsible for hemostasis. When ovulation does not take place, progesterone levels do not rise; therefore, typical cyclic withdrawal of estrogen and progesterone cannot occur.
Normal menstrual cycles are characterized by a cycle length of 28 days (+/- 7 days), a duration of flow of 4 days (+/- 2 days), and a blood loss of 40 mL (+/- 20 mL).
Types and definitions
Cycle length >35 days
Cycle length <21 days
Absence of menses
Regular cycles; excessive flow, longer duration
Cycle length <21 days with heavy flow, longer duration
Causes of abnormal uterine bleeding
1.Abnormalities of the reproductive tract
Benign pelvic lesions
Polyps, cervical or endometrial
Malignancy [cancer of the uterus, cervix, vagina or ovaries]
when no other cause can be found. Dysfunctional uterine bleeding is a diagnosis of exclusion. In the vast majority of cases, it is secondary to anovulation [a condition where the follicle does not burst and therefore does not release the egg], which is more common at the extremes of reproductive age ie: teenage girls an women between 40-50 years of age.
Ultrasound in AUB
Transvaginal USG is much preferred to trans abdominal USG. In TVS [trans vaginal sonography] a probe is placed inside the vagina to evaluate the uterus, ovaries and pelvis. This is much more sensitive and has a better diagnosis rate than trans abdominal USG. USG looks for fibroids, polyps, ovarian tumours as well as the endometrial thickness.
Importance of endometrial thickness [thickness of the lining of the uterus]
Post menopausal patients with an endometrial thickness of more than 4mm and with vaginal bleeding should have a biopsy taken. A post menopausal patient who has a routine screening [without any history of vaginal bleeding] and is found to have an endometrial thickness of 10mm or more should also undergo a biopsy.
However rigid reliance on ultrasound measurement is inadvisable, especially when clinical symptoms suggest pathology.
Currently, there is no accepted cut-off value for premenopausal women with abnormal uterine bleeding that could differentiate normal from abnormal endometrium. This is why age is often used as a criteria – pre menopausal patients above the age of 35 require endometrial sampling.
Importance of D&C with office Hysteroscopy
However any woman over 35 years of age with abnormal uterine bleeding should undergo endometrial evaluation by a D&C combined with a hysteroscopy [hysteroscopy makes the chances of picking up and locating a cause much higher so ideally hysteroscopy & D&C is always to be preferred to a plain D&C].
Treatment of AUB
Treatment of abnormal uterine bleeding varies, depending on the cause. For example if fibroids are found they need to be removed either by myomectomy or hysterectomy, and if cancer is found the appropriate treatment needs to be given.
If no cause is found then the patient is labelled as having dysfunctional uterine bleeding [DUB], diagnosis by exclusion.
If this type of bleeding is suspected but treatment fails, other causes should be investigated. The goals in treatment of dysfunctional uterine bleeding are to control bleeding, prevent recurrences, and preserve fertility if the patient requires it. The choice of treatment depends on whether bleeding is acute or chronic.
When bleeding is acute, the first step is to determine if the woman’s condition is hemodynamically stable [pulse and blood pressure are maintained or not]. A patient with signs of hypovolemia [low BP, high heart rate] should undergo volume resuscitation, be hospitalized and most clinicians proceed to dilation and curettage, which quickly controls bleeding.
The hemodynamically stable patient with acute heavy bleeding should be treated with estrogen. The most convenient method of estrogen administration is use of low-dose oral contraceptives.
After finishing the course of oral contraceptives, the patient typically experiences a heavy, crampy period. She should continue to take low-dose oral contraceptives for at least another 3 months and then undergo reevaluation to determine whether treatment for chronic bleeding is indicated.
Treatment of patients with chronic recurrent bleeding is based on their reproductive desires. Patients who want birth control can use low-dose oral contraceptives. If contraception is not desired, use of cyclic progestins for the first 10 days of each month is the treatment of choice. Patients wishing to become pregnant are candidates for ovulation inducing drugs.
In addition to these measures some patients may be given a trial of drugs such as Mefanamic Acid and Tranexemic Acid which can reduce the bleeding at the time of the periods.
In the cases in which dysfunctional uterine bleeding does not respond to any of the management options described, hysterectomy is an option for those patients who have finished child bearing and are no longer interested in retaining their fertility.
A reasonably common finding on biopsy is endometrial hyperplasia - the treatment of this may be either medical or surgical depending on the degree of hyperplasia, age of the patient and the willingness of the patient to follow up with repeated biopsies or not.
You may need surgical treatment for menorrhagia if drug therapy is unsuccessful. Treatment options include:
Dilation and curettage (D&C). In this procedure, your doctor opens (dilates) your cervix and then scrapes or suctions tissue from the lining of your uterus to reduce menstrual bleeding. Although this procedure is common and often treats menorrhagia successfully, you may need additional D&C procedures if menorrhagia recurs.
Operative hysteroscopy. This procedure uses a tiny tube with a light (hysteroscope) to view your uterine cavity and can aid in the surgical removal of a polyp that may be causing excessive menstrual bleeding.
Endometrial ablation. Using a variety of techniques, your doctor permanently destroys the entire lining of your uterus (endometrium). After endometrial ablation, most women have little or no menstrual flow. Endometrial ablation reduces your ability to become pregnant.
Endometrial resection. This surgical procedure uses an electrosurgical wire loop to remove the lining of the uterus. Both endometrial ablation and endometrial resection benefit women who have very heavy menstrual bleeding. Like endometrial ablation, this procedure reduces your ability to become pregnant.
Hysterectomy. Surgical removal of the uterus and cervix is a permanent procedure that causes sterility and cessation of menstrual periods. Hysterectomy is performed during anesthesia and requires hospitalization. Additional removal of the ovaries (bilateral oophorectomy) may cause premature menopause.
Except for hysterectomy, these surgical procedures are usually done on an outpatient basis. Although you may need a general anesthetic, it’s likely that you can go home later on the same day.
When menorrhagia is a sign of another condition, such as thyroid disease, treating that condition usually results in lighter periods.
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