Oligomenorrhea (or oligomenorrhoea) is infrequent (or, in occasional usage, very light) menstruation.More strictly, it is menstrual periods occurring at intervals of greater than 35 days, with only four to nine periods in a year. Also, menstrual periods should have been regularly established previously before the development of infrequent flow. The duration of such events may vary.
Oligomenorrhea can be a result of prolactinomas (adenomas of the anterior pituitary). It may also be caused by thyrotoxicosis, hormonal changes inperimenopause, Prader–Willi syndrome, and Graves disease. "Endurance exercises such as running or swimming can affect the reproductive physiology of women athletes. Female runners, swimmers and ballet dancers menstruate infrequently in comparison to nonatheletic women of comparable age or not at all (amenorrhea). The degree of menstrual abnormality is directly proportional to the intensity of the exercise. For example, have shown menstrual irregularity is more common, and more severe among tennis players than among golfers" (modified by a student paper written by A. Lord) Breastfeeding has also been linked to irregularity of menstrual cycles due to hormones which delay ovulation.
Women with polycystic ovary syndrome (PCOS) are also likely to suffer from oligomenorrhea. PCOS is a condition in which excessive androgens (male sex hormones) are released by the ovaries. Women with PCOS show menstrual irregularities that range from oligomenorrhea and amenorrhea, to very heavy, irregular periods. The condition affects about 6% of premenopausal women and is related to excess androgen production.
Eating disorders can also result in oligomenorrhea. Although menstrual disorders are most strongly associated with Anorexia nervosa, Bulimia nervosa may also result in oligomenorrhea or amenorrhea. There is some controversy regarding the exact mechanism for the menstrual dysregulation, since amenorrhea may sometimes precede substantial weight loss in some anorexics; thus some researchers hypothesize that some as-yet unrecognized neuroendocrine phenomenon may be involved, and the menstrual irregularities may be related to the biological undergirding of the disorders, rather than a result of nutritional deficiencies.
Causes and symptoms
History and physical examination
Oligomenorrhea is a medical term which generally refers to irregular or infrequentmenstrual
periods with intervals of more than 35 days - however, the duration may vary.
A period, or menstruation, is the shedding of
the endometrium - the lining of the uterus. Menstruation is also called menses.
All female humans, as well as a number of other female mammals, have regular
periods during their reproductive age. Menstruation, which includes bleeding
from the vagina, occurs mainly among humans and similar animals, such as
primates. In many mammals, the endometrium is reabsorbed.
As far as humans are concerned a period is a
bleed from the womb (uterus) that is released through the vagina. Human females
have a period about every 28 days - most women have between 11 and 13 menstrual
periods each year. However, some women may have a 24-day cycle while other may
have a 35-day one. A period is part of the female's menstrual cycle.
Periods usually start between the ages of 10 and
16 (during puberty), and
continue until themenopause, when woman
is 45 to 55 years old. Periods can take up to two years to occur in a regular
cycle. After puberty, the majority of females have a regular menstrual cycle
(the length of time between each period is similar).
Menstrual bleeding usually lasts for about five
days, but can vary from two to seven days.
Some women have irregular periods - the time
between periods, as well as the amount of blood shed varies considerably. This
may have several possible causes, including a change incontraception method, a hormone
imbalance, hormonal changes in perimenopause, and endurance exercises.
Treatments for irregular periods during puberty
and around the menopause are not usually necessary, as they are quite common. What are the causes of irregular periods?
are two main reasons for irregular periods:
§ A change in the contraception method
§ An estrogen and/or progesterone imbalance (hormones which regulate the menstrual cycle)
- Polycystic ovarian syndrome (polycystic ovary system) - also known as PCOS, or the
Stein-Leventhal Syndrome. Many cysts (small, fluid filled sacs) develop in the ovaries. It
is a condition characterized by irregular or no periods, obesity, acne, and excess hair growth.
Women with PCOS have a disorder of chronically abnormal ovarian function
and abnormally high levels of androgen (hyperandrogenism). Androgen is a
male sex hormone - the major androgen is testosterone.
According to the CDC (Centers for Disease Control and Prevention), USA,
approximately 5% to 10% of women of reproductive age are affected by PCOS.
A woman with PCOS does not release an egg every month (she does not
ovulate). Patients with PCOS have a considerably higher risk of
hypertension (high blood pressure),diabetes, heart disease and endometrial cancer (cancer of
the uterus). Experts say that in many cases weight loss and exercise can
eliminate much of the risk.
- A woman's imbalance of hormones, which may lead to irregular periods, may also be
- Extreme weight loss. Low body weight is a common cause of irregular or missed periods.
- Extreme weight gain.
Obesity may sometimes cause menstrual problems.
- Emotional stress
- Eating disorders, such as anorexia or bulimia can lead to hormone imbalances, resulting in irregular
or missed periods.
- Endurance exercises - endurance athletes, such as those that compete in
marathons, may have irregular or missed periods.
- Puberty -
irregular periods for a few years after puberty are common, and not
considered unusual. It may take a few years for the hormones that control
menstruation - estrogen and progesterone - to reach a balance.
- Before the menopause - as the menopause approaches women commonly have
irregular periods. The amount of blood shed may also vary. Menopause
occurs when it has been 12 months since the woman has had a menstrual
- Breast feeding - most
women do not start having periods again until they stop breastfeeding.
- Thyroid disorder -
irregular periods may be caused by a thyroid disorder. The thyroid gland
produces hormones that affect our bodies' metabolism.
- Contraceptives - an IUD
(intrauterine device) may cause heavy bleeding, while the contraceptive
pill can cause spotting between periods. Initially, when using the
contraceptive pill for the first time, it is not uncommon for the woman to
experience breakthrough bleeds (small bleeds). Breakthrough bleeds are
generally shorter and lighter than normal periods - they usually go away
after a few months.
- Cancer - bleeding between periods may be caused by cervical cancer or uterine cancer (cancer of the uterus/womb). These
cancers may also cause the woman to bleed during sex. Bleeding caused by
these cancers is rare.
- Emdometriosis - this is a condition in which cells that are normally
found inside the uterus (endometrial cells) are found growing outside it.
That is, the lining of the inside of the uterus is found outside of it.
Endometrial cells are the cells that shed every month during menstruation,
and so endometriosis is most likely to affect women during their
childbearing years. The cellular growth is not cancerous, but benign.
Though there are not always symptoms, it can be painful and lead to other
Problems may occur if released blood gets stuck in surrounding tissue and
damage it, causing severe pain, irregular periods and infertility.
- Pelvic inflammatory disease - an infection of the female reproductive system. It is
the most common and serious complication of sexually
apart from AIDS, among women. If detected early it can be treated with antibiotics. However, if it spreads and damages the fallopian
tubes and uterus it can result in chronic episodes of pain (in medicine
"chronic" means long-term, for life). Of the many symptoms are
included bleeding between periods and after sex.