Womens Health

Types of Irregular Menstrual Patterns

Frederick R. Jelovsek MD

"What daily hormone supplement do you recommend to improve an irregular menstrual cycle? " SS

Irregular menses, as measured from the start of one menses to the start of another, seem to occur in two patterns:

  • Onset of menses varies irregularly from about 3 weeks to 6 weeks but not skipping a month altogether. It is called metrorrhagia if many of the menses are less than 4 weeks.
  • Onset of menses varies from 4 weeks to 3-6 months having perhaps only 2-6 menses a year. This is called oligomenorrhea, infrequent menses.

Oligomenorrhea, the infrequent, irregular menses pattern is caused by lack of ovulation. However, it may further be subdivided into a low estrogen type in which there are no follicles being developed and a high estrogen type in which the follicles are developed but they are arrested so none of the eggs are released (ovulated) from the ovary.

To answer the question above, we really need to identify what type of irregular menses is involved as well as the goals of treatment. For example, is the goal just to have a more predictable menstrual flow or is it to try to time intercourse in order to improve the chances of conception? Is the goal to be more regular so that a rhythm method of contraception works or to plan work or leisure events so as to avoid interruption by a mense?

Common Questions

What are some of the causes of irregular, more frequent menses (metrorrhagia)?

Causes of the metrorrhagia irregular menses pattern are unknown or are more likely related to stresses and ingested medications or substances that disrupt corpus luteum function or even act as anticoagulant blood thinners. Caffeine may act this way and disrupt corpus luteum function. Heavy caffeine consumers tend to have twice the risk of short cycle length (less than 24 days) (1). Their cycles are not heavier but they are often more frequent.

Cigarette smoking is another agent that can shorten menstrual cycles (2). Cigarettes seem to shorten the follicular phase but heavier smoking also may shorten the luteal phase. Both heavy smoking and even smoking just 10 cigarettes or more a day may cause menstrual cycles to be shorter in length, as well as more variable in their lengths than nonsmokers.

Acute or excessive alcohol ingestion, getting drunk on occasion, is also known to alter menstrual patterns (3). Sometimes it shortens cycles while at other times it can cause a delay of menses. The alcohol is thought to affect the liver's ability to properly metabolize estrogen and progesterone.

What makes a woman not ovulate at all and have low estrogens?

There are many things that can block ovulation in women. Stress is the most common cause. Eating disorders such as bulimia and anorexia also cause low estrogen and menstrual delay (4). If there are no menses at all, this is called hypothalamic amenorrhea. The mechanism for this is not totally known but probably has to do with alteration of brain proteins and hormones so that the normal ovulatory releasing factors do not work. When the brain releasing factors do not stimulate follicle development, there are few estrogens produced and a woman is then at risk for osteoporosis at a young age. This is why physicians prescribe estrogens in this condition, i.e., to prevent bone loss.

Recreational running does not seem to change menstrual cycle length (5), but strenuous endurance running can disturb cycle length (6) and make a woman anovulatory. Long distance runners and other strenuous sports have been well known to cause anovulation of the low estrogen type. There has even been a suggestion that being a vegetarian may increase the risk of anovulation (7, 8).

What causes irregular, infrequent menses and high estrogens?

While the most common cause of irregular delayed menses is due to stress type hypothalamic amenorrhea, the next most frequent type is due to polycystic ovarian syndrome. This is a complex condition of the ovaries in which follicles seem to grow and produce estrogen but the egg does not get released. This results in a high estrogen condition but infrequent menses. When the period does start, it often can be a very heavy one that persists for days or even weeks. The continuous, high estrogens cause the uterine lining to grow and proliferate and eventually it gets too thick and then sloughs off causing a menstrual like bleed. Because of the chronic and continuous estrogen stimulation, most doctors feel that a menstrual period should be induced with hormones (progesterone/progestin) so that a woman is not at risk for endometrial cancer.

Women who have polycystic ovarian syndrome (PCOS) will frequently have abnormal carbohydrate metabolism called insulin resistance or even develop diabetes. Additionally, excess hair growth due to extra testosterone occurs in many women with PCOS.



What is the best non-prescription treatment to make menses more regular?


For a metrorrhagia type of irregular menstrual pattern, it is important to give up tobacco, alcohol and cut caffeine servings down to 2 or less per day. Try to minimize any medications that you do not have to take. If menses are mildly irregular and you are trying to time conception, taking a phytoestrogen supplement on a daily basis may help stabilize the menstrual cycle length.

For a low estrogen, irregular menstrual problem, the key treatments are:

  • stress reduction and/or relaxation techniques
  • elimination of overly strenuous physical exercise
  • eliminate any eating disorders such as purging, bulimia, or anorexia
  • take supplemental, measured estrogens such as phytoestrogens in soy or clover products

For a high estrogen irregular menses pattern such as that found in PCOS, weight reduction using a low carbohydrate diet is essential. Even a 10% weight loss will help restore normal menstrual patterns in obese women who are anovulatory (9).

What are the best prescription treatments for menstrual irregularities?

Oral contraceptives (OCPs) are the most commonly used hormonal treatment for irregular menses. They do not correct the underlying problem that causes the irregularity but they will regulate the pattern very precisely to the same day of the week each cycle. In general, oral contraceptives are very safe and will not cause an alteration in the body even after taking for a very long time. Some women cannot take birth control pills, however, so other treatments are also used.

Women with irregular menses due to hypothalamic factors can take a sequential hormone regimen. In this regimen, estrogen is given each day and then progesterone is given for 10-14 days each month in order to induce a withdrawal bleed. This regimen will not protect against pregnancy should ovulation occur so if a pregnancy is desired, this may be the best regimen.

For polycystic ovarian syndrome most physicians will prescribe oral progestins or progesterone to take for 10 days every two months if there has not been a spontaneous menses. This is thought to protect against the development of endometrial cancer or hyperplasia from the long term elevation of estrogens.

Carbohydrate metabolism abnormalities are often successfully treated with a combination of diet and medications, and the menstrual irregularities may disappear. Metformin, a drug which reduces high insulin levels has been shown to make women with PCOS resume normal menses in almost 90% of cases (10 ). This is a dramatic breakthrough in treatment and one worth seeing your physician about if you have PCOS.


Other Related Articles

Prolonged and Heavy Perimenopausal Bleeding
Lifestyle Choices and Female Infertility
Bleeding While on Hormone Replacement
Non Hysterectomy Fibroid Treatments Including Embolization
Post Tubal Ligation Syndrome
Diagnosis of Polycystic Ovarian Syndrome
Breast milk hormone (prolactin) and anovulation
Saline Infusion Sonography Diagnosis of Bleeding


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