Dysfunctional Uterine Bleeding (DUB)

DUB is divided into 2 groups as ovulatory and anovulatory according to ovulation factor.

  1. Ovulatory (ovulation) dysfunctional bleeding

Bleeding with the presence of ovulation in women of reproductive age constitutes 10% of normal dysfunctional bleeding. Ovulatory dysfunctional bleeding is characterized by regular but excessive menstrual blood loss, with 90% of blood loss occurring in the first 3 days of menstrual bleeding.

The hypothalamic-pituitary-ovarian axis is intact and the hormonal profile is not different from normal cycles.

Estrogen and progesterone in the late luteal phaseThe decrease in the levels of the endometrium causes separation and reepithelialization in the functional layer of the endometrium.

In the mechanism of ovulatory dysfunctional bleeding

1) increased local prostaglandin synthesis

2) abnormal receptor regulation,

3) increased local fibrinolytic activity,

4) elevation of tissue plasminogen activatorone,

5) It has been shown that the rate of vasoconstrictor (PGF2a) vasodilator (PGE2) in the endometrium is high in favor of vasodilator.

Ovulatory dysfunctional bleedings include: 1) oligomenorrhea 2) polymenorrhea 3) ovulation bleeding 4) luteal phase failure 5) prolongation of corpus luteum activity:

Oligomenorrhea: Due to the relative (FSH) deficiency, follicle development is delayed and the follicular phase is prolonged. As a result, bleeding that occurs at intervals longer than 35 days (oligomenorrhea) occurs.

Polymenorrhea: It is bleeding that occurs regularly in less than 21 days and is characterized by shortening of the follicular phase. Usually, due to the hypersensitivity of the immature ovary to gonadotropins, the follicular phase is shortened and frequent menstrual bleeding (polymenorrhea) occurs.

Ovulation bleeding:It is the inter-cycle bleeding in the form of spotting as a result of the relative decrease in estrogen following ovulation in the middle of the cycle.

Luteal phase failure: Dysfunctional hemorrhages can be seen in luteal phase insufficiency caused by insufficient progesterone secretion. Bleeding due to luteal phase insufficiency usually occurs as a premenstrual spot (spotting) and is sometimes characterized by menorrhagia.

Prolongation of corpus luteum activity:It occurs as a long cycle (oligomenorrhea) or prolonged menstrual bleeding (menorrhagia) in the persistence of the corpus luteum, which occurs as a result of the continuation of progesterone production despite the absence of pregnancy.

Anovulatory dysfunctional hemorrhages – DUKs are generally 90% anovulatory causes. Anovulatory dysfunctional hemorrhages are seen especially in adolescents, obese patients in premenopausal period and patients with PCOS.

During the perimenopausal transition, progressive oocyte depletion and abnormal follicle development lead to anovulatory cycles.

Causes of anovulation

  • Physiological 

  • adolescent

  • perimenopause

  • lactation

  • Pregnancy

  • pathological 

  • Hyperandrogenic anovulation (for example, PCOS, CAD, or androgen-secreting tumors)

  • Hypothalamic dysfunction (for example, secondary to anorexia nervosa)

  • hyperprolactinemia

  • thyroid disease

  • Primary pituitary disease

  • premature ovarian failure

  • Iatrogenic (for example, due to radiation or chemotherapy)

  • Medicines

The most common cause of anovulation (from ovulation) is pregnancy. It is frequently observed in adolescents due to the incomplete development of the hypothalamic-pituitary-ovarian axis within 2 years. Classically, in this period, although the hypothalamic-pituitary-ovarian axis has enough FSH secretion to cause estrogen to be synthesized from the ovaries and eventually to proliferate in the endometrium, it is not mature enough to fully develop the follicle, to ovulate, and to maintain cyclic menses. The endometrium is stimulated by estrogen for a long time without the suppressive effect of progesterone. This leads to continuous proliferation of the endometrium. Since there is no progesterone secretion in women who do not ovulate, the endometrium continues to proliferate. As a result of continuous estrogen effect or decrease in estrogen level, the endometrium sheds and bleeds. This type of withdrawal or fracture bleeding is the most common form of dysfunctional bleeding. It constitutes 90% of dysfunctional bleedings. By definition, anovulatory women are always in the follicular phase of the ovarian cycle and the proliferative phase of the endometrial cycle. Differential diagnosis. The diagnosis of anovulatory DUB is based on exclusion of other causes. Pregnancy and the possibility of pregnancy complications should always be kept in mind and ruled out. Although abnormal bleeding is frequently seen in patients using hormonal contraception and other forms of external hormone therapy, it should be kept in mind that there may be an underlying pathology (cervical and endometrial polyps, fibroids adenomyosis, malignancies of the cervix and endometrium).

coagulation disorderIt should definitely be kept in mind that it may occur, especially in adolescents whose menstrual history is short and incompletely completed.

The most common cause of abnormal uterine bleeding in adolescents is anovulation, but coagulation disorders can be found in up to one-third of them.

Coagulation disorders are often associated with cyclic heavy and prolonged bleeding periods.

The same pattern can be seen in women receiving anticoagulant therapy.

Coagulation disorders are not as uncommon as usually perceived and can be found in 10-20% of women with unexplained menorrhagia.

It should be questioned whether to take drugs and herbal products that may cause abnormal bleeding tendency, such as glucocorticoids, ginkgo, tamoxifen and anticoagulants.

Other less common diagnostic possibilities include serious systemic diseases (kidney or liver failure), genital trauma, and foreign bodies.

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