Irregular Menstrual Cycles and Their Connection to Anemia - Obstetrics and Gynecology

Dr. Chen Fuhao reply Obstetrics and Gynecology

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"Hello! The so-called normal menstruation occurs under conditions of normal female endocrine function, characterized by periodic and regular ovulation, followed by the shedding of the endometrium and bleeding.
The typical cycle ranges from 21 to 35 days.
Dysfunctional uterine bleeding (DUB) refers to abnormal bleeding caused by endocrine disorders, without any diseases of the reproductive or non-reproductive organs, such as tumors, inflammation, or complications associated with bleeding during pregnancy.
Since almost all women experience one or two instances of excessive or insufficient bleeding, or prolonged or shortened menstrual periods, some scholars believe that dysfunctional uterine bleeding is defined as irregular menstruation lasting more than three months.
Menstrual disorders are common, accounting for about 21% of gynecological outpatient visits.

Before classification, it is essential to familiarize oneself with several terms commonly used to describe the volume of bleeding, duration of bleeding, and various irregular cycle conditions:
(1) Menorrhagia (hypermenorrhea) - increased volume and duration of uterine bleeding, with regular intervals between episodes.
The definition of regular heavy menstrual bleeding is a blood volume greater than 80ml.
Women may subjectively report their symptoms—some may describe normal amounts as excessive, while others may endure heavy bleeding.
Careful inquiry about the type of pads or menstrual cups used, the number changed daily, the amount of blood clots, and the frequency of soiling clothes or sheets is helpful.
A menstrual diary can be beneficial.
Causes of heavy menstrual bleeding may include: unknown reasons, uterine fibroids, bleeding disorders, intrauterine devices (except for Mirena), and pelvic infections (usually associated with heavy and painful menstruation).

(2) Hypomenorrhea - regular cycle with reduced bleeding volume.

(3) Metrorrhagia - normal bleeding volume with highly irregular intervals.

(4) Menometrorrhagia - irregular and excessive bleeding in both volume and duration.

(5) Polymenorrhea - regular bleeding cycles occurring less than 21 days apart.

(6) Oligomenorrhea - irregular bleeding cycles occurring more than 45 days apart.

(7) Intermenstrual bleeding - non-menstrual bleeding occurring between regular menstrual periods, possibly related to physiological factors and sudden rises (and falls) in estrogen during ovulation.
More commonly, it is associated with cervical or endometrial polyps, cervical erosion, and occasionally cervical cancer or stress.
Postcoital bleeding is also related to the same causes.
The definition of functional uterine bleeding refers to significant and regular bleeding without pelvic pathology, pregnancy, or bleeding disorders.
Both hyperthyroidism and hypothyroidism can lead to irregular menstruation, necessitating differential diagnosis.
Dysfunctional uterine bleeding can be categorized into anovulatory bleeding and ovulatory bleeding.
Anovulatory dysfunctional bleeding occurs due to the absence of ovulation, resulting in insufficient luteinization of the endometrium, leading to abnormal production of prostaglandins and steroid receptors.
If exogenous estrogen levels remain elevated, it can cause endometrial proliferation or hyperplasia, resulting in painless bleeding.
The specific term for long-term heavy uterine bleeding is metropathia haemorrhagica.
The endometrium may exhibit typical cystic structures referred to as "Swiss cheese." Poor positive feedback during anovulatory cycles prevents the production of the LH surge necessary for ovulation.
Follicular dysplasia may occur in patients nearing menopause or with polycystic ovary syndrome.
If follicular development is inadequate, there will not be sufficient estrogen signaling, preventing the LH surge and subsequent ovulation.
Ovulatory dysfunctional bleeding results from poor luteal phase function due to inadequate corpus luteum production, leading to irregular bleeding and is associated with infertility.
Unexplained ovulatory dysfunctional bleeding may be related to endogenous prostaglandin imbalance.
Dysfunctional abnormal bleeding can occur during ovulatory cycles or may be anovulatory.
The former accounts for about 10% and is more common in the reproductive age group, while the latter accounts for 90% and is more prevalent during puberty and perimenopause.
Hormones are complex and involve central factors (including the hypothalamus, pituitary gland, or emotional disturbances), ovarian defects, and metabolic factors, all of which can disrupt the balance of hormones such as estrogen and progesterone, leading to clinically disruptive uterine bleeding.
Prolonged heavy bleeding can cause dizziness, pallor, fatigue, and shortness of breath.
A general blood test can help determine if there is anemia.
In diagnosis, one should start with a thorough medical history, physical examination, and special tests (such as endometrial biopsy, hysteroscopy, hormone level quantification, hematological tests, liver function tests, vaginal cytology, and basal body temperature monitoring).
Treatment depends on the patient's age, reproductive goals, and contraceptive needs.
Therefore, the treatment objectives are threefold: (1) to stop acute bleeding, (2) to prevent recurrence, and (3) to restore reproductive function, which includes achieving ovulatory cycles.

In summary, I believe you now have a better understanding.
However, since diagnosis and treatment involve specialized fields, if you have any further questions, I recommend consulting a gynecologist.
Wishing you health and happiness! Reference: Clinical Gynecology (Author: Wu Hsiang-ta)."

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Reply Date: 2007/05/16